But that’s not the case with the experts below. They’re all well-known for their mastery of CSS and all that goes along with it. Read on for their tips and tricks with regards to everything from avoiding hacks to understanding the box model.

Peter-Paul Koch: Avoid CSS Hacks
As web design has progressed, the endlessly nested table has transformed into the endlessly complicated CSS hack. In many cases, CSS hacks solve one bug by exploiting another one; not exactly the most stable way to fix something. When the next version of the browser is released, it might fix neither or both bugs, or it might fix one but not the other. In any case, it’s likely your hack might end up not working, or not being necessary any longer.

Jonathan Snook: Avoid Unnecessary Selectors
To keep your style sheets as short and condensed as possible, avoid repeating yourself by only specifying the minimum number of selectors. In other words, do you really need to specify UL and LI? Why not just specify the UL? The same goes for other elements likely to be nested. Just specify the upper-most level and leave the rest to inherit those styles.

Roger Johansson: Specify a Maximum Width for Em-Based Layouts
Creating an elastic layout that don’t specify a maximum width in anything other than em units is a quick way to make a very uncomfortable site. As your visitors increase the text size, your layout gets wider. But what happens when they increase the size by more than one or two em units? Your layout just gets wider and wider and pretty soon they have to scroll horizontally in order to read an entire line. Specify a maximum width to avoid that problem and make your site more user-friendly.

Trevor Davis: Set a Consistent Base Font Size
By setting your base font size at 62.5%, you end up with a font size of 10 pixels. This makes 1 em equal to 10 pixels. 1.2 em is then equal to 12 pixels. It simplifies font sizing in all of your selectors thereafter.

Dan Cederholm: Use Negative Margins
Using negative margins can greatly simplify your code. Instead of specifying positive margins for a dozen or more elements, why not just specify a negative margin for one? It makes your style sheets shorter and less complex.

Ben Henick: Don’t Add Markup Unless Context Encourages It
When transitioning from table-based layouts, many designers are tempted to add in an abundance of container elements. But CSS isn’t the same as tables. Thinking through your design ahead of time is one way to avoid this, as is focusing on the information first. Try to only use divs and spans for content elements that share a common purpose or classification and are repeated across multiple pages.

Eric Meyer: Use Print-Specific Style Sheets
Forget about creating separate printer-friendly pages for your content. Use CSS to create media-specific styles for your documents instead. Printer-friendly style sheets are easy to create and avoid problems designers used to encounter regarding the regular version and printer-friendly version being slightly different from each other. After all, with this method you’re not touching the page markup at all.

Wolfgang Bartelme: Center with CSS
For people just starting out with CSS, centering an entire website can sometimes seem like an impossibility. But it’s definitely possible and actually relatively easy to achieve.

Trenton Moss: Use Mobile-Specific Stylesheets
With more and more people browsing the web primarily through mobile devices, it’s important to make sure your website is optimized for those visitors. While most handhelds will render pages reasonably well using standard CSS, it’s still not the best user experience on a 3″ screen. Create a separate mobile style sheet to optimize the experience for mobile users.

Chris Coyier: Use the CSS Overflow Property Correctly
There are four different values available for the CSS overflow property: hidden, visible, scroll, and auto. By understanding what each of these does and how each behaves, you open up a lot more options for your site’s layout.

Ethan Marcotte: Create Fluid Grids with CSS
The idea of creating a fluid grid design, especially with CSS, is likely to send shivers down the spines of many web designers. But it is possible, and is definitely preferable to creating them with tables.

Jonathan Snook: Use CSS Shorthand
Using shorthand is another way to simplify and shorten your stylesheets. Instead of declaring separate styles for each margin (margin-left, margin-right, margin-top, margin-bottom), just declare them for all four at one time. The same goes for other elements, such as font, border, or background.

Chris Coyier: Understand the CSS Box
Everything element in CSS is a rectangular box. Padding, margins, height, width and borders all interact with these rectangular boxes. Gaining a real understanding of how these things interact will make life as a designer infinitely easier.

Roger Johansson: Be Wary of Hiding Things With CSS
It’s tempting when you want to hide an element on your page to use “display:none.” The problem with this, though, is that this particular declaration means that the contents within that element are completely hidden—they aren’t printed, displayed, or spoken. This can cause issues for those using screen readers as opposed to viewing your website. It can also cause issues when you’re going to hide something until a user performs a certain action (most likely with JavaScript).

Peter-Paul Koch: Know When to Use Strict Mode or Quirks Mode
Strict mode and quirks mode apply to the two different ways modern browsers use to interpret CSS. By understanding what each one does and then implementing the correct one for your design, you can greatly improve your site’s functionality.

1. Build a WordPress 2.8 Widget with New Widget API – WPEngineer
http://wpengineer.com/wordpress-built-a-widget/
WPEngineer Michael Preuss walks you through the new simpler Widget API in WordPress 2.8 to create a simple widget. Very simple and easy to understand tutorial.

2. The Complete Guide To Creating Widgets in WordPress2.8 – Justin Tadlock
http://justintadlock.com/archives/2009/05/26/the-complete-guide-to-creating-widgets-in-wordpress-28
This is another great resource to learn how to build a widget using the new Widget API by Justin Tadlock.

3. Tutorial on WordPress 2.8 Widget API – Jesse Altman
http://jessealtman.com/2009/06/08/tutorial-wordpress-28-widget-api/
Another easy to understand hello world tutorial on working with new WordPress widget API.

4. Custom Taxonomies in WordPress 2.8 – Justin Tadlock
http://justintadlock.com/archives/2009/05/06/custom-taxonomies-in-wordpress-28
If you find categories and tags too restricting for the stuff you write, Justin Tadlock explains how to define your own taxonomies in WordPress 2.8 to label your posts in the way you want.

5. WordPress 2.8 and body_class() function – Nathan Rice
http://www.nathanrice.net/blog/wordpress-2-8-and-the-body_class-function/
WordPress 2.8 supports location-specific classes for body tag with which you can control the looks of almost everything with just CSS.

6. Load JavaScript Files in Footer of Your Theme – Lester Chan
http://lesterchan.net/wordpress/2009/01/26/loading-javascript-in-footer-in-wordpress-28/
Now you can make your WordPress blog faster by loading JavaScript files in the footer. Lester Chan explains how to do that in WordPress 2.8

7. Displaying Author Meta Information in WordPress 2.8 – Zach Dunn
http://buildinternet.com/2009/06/displaying-author-meta-information-in-wordpress-2-8/
WordPress 2.8 include two new functions the_author_meta() and get_the_author_meta() to display information about authors. Zach Dunn explains how to use these new functions in your WordPress theme.

8. the_author_meta() in WordPress Codex
http://codex.wordpress.org/Template_Tags/the_author_meta
The WordPress codex explains the new author meta information methods, its parameters and examples.

9. Handling Plugin Options in WordPress 2.8 – PlanetOzh
http://planetozh.com/blog/2009/05/handling-plugins-options-in-wordpress-28-with-register_setting/
WordPress 2.8 includes interesting register_setting() function that lets plugin authors leave the dirty stuff to WordPress and concentrate on the functionality of plugin.

10 WordPress Proxy Support – WP Engineer
http://wpengineer.com/wordpress-proxysupport/
If you are using WordPress on your local network which is behind a proxy, then now you can easily fetch content from other websites or RSS feeds as WordPress 2.8 requires just a little edition to wp-config.php to work behind a proxy.

If you know of some other nice tutorials on WordPress 2.8, feel free to share them with us.

1. It should still look like your website
If you don’t specifically tell your web server how to handle 404 errors, it will serve up a very plain and generic looking error page. That just says something like “Not Found – The requested URL was not found on this server.” on a plain white page. This is an unhelpful and rather painful roadblock for a user. A 404 page should look like an error page, but it should still look like your website. If you are using a CMS, this is probably already handled for you. If you have a static site, you can specify a 404 template through your .htaccess file.

2. Apologize
Nobody is trying to land on your 404. Most likely they came from a bad link either on your own site or out in the wild. They probably aren’t very happy about it, so this is a golden opportunity to apologize and hopefully turn that frown upside down.

3. Search
It’s possible the page they are looking for still exists, it’s just the URL has changed or it was incorrectly typed somewhere. Since your site should already have search anyway, this is a good opportunity to provide that search box front-and-center. This gives the user the opportunity to search for what they were trying to link to and dig up the correct URL for themselves.

4. Give readers useful links
Maybe the page they are linking to isn’t broken, it just doesn’t exist anymore. In addition to search, you may want to dish out some links they will find useful. Perhaps links to the homepage, the archives page, or other pages you already know are commonly visited / popular pages on your site?

5. Way to Contact / Report Error
It is possible a user landing on a 404 page is having some strong emotions about it. They could be very concerned, worried, or they could be down right ticked off. It is a good idea to give that user some way to release, and since you can’t hand them a punching bag, a contact form might do the trick. This is, of course, not only good for them but good for you, as you can learn about the problem in order to fix it or otherwise prevent it from happening again.

6. Automatic Reporting
Having users help report errors for you through a contact form is great, but only a small percentage of users are likely to do that. An alternative is to have your 404 page automatically report the error to you. There are many ways you could do this. A quick-and-dirty way to do it would be to make your 404 page a PHP file, and use the mail function to send an email of the URL that was landed on.

7. Humor
Even serious sites can get away with a little humor on the 404 page. This is definitely a good opportunity to loosen up a little and do something funny.

8. Redirect?
I’m on the fence about this one, but it’s possible to automatically redirect a 404 error to another page. Perhaps the homepage displaying a message about the error? Perhaps a search page with keywords from the URL parsed out?

9. File Size
You might be surprised at the amount of malicious activity that your web server has to deal with. One thing that surprised me a while back was how many requests there were for “weird” files. Things like requesting the favicon in strange subfolders or looking for random images that don’t exist. When these things don’t turn up, the server loads up your 404 page. Needless to say, serving up a full webpage for all these requests adds up to some serious bandwidth. Your best bet is to fight against these malicious requests, but you should also take care to consider the total page size of your 404 page size and reduce it if bandwidth is a major concern.