CSS tips

I was browsing Design Reviver today and found this great article: 13 Training Principles of CSS Everyone Should Know. The great thing about this article is that the suggestions are smart, but they aren't necessarily obvious. I see mistakes like he lists all the time. He suggests things like naming your CSS classes intelligently, using CSS shorthand, and using the correct DOCTYPE. But he also talks about using CSS frameworks (or pre-made templates) and not declaring default values. These kinds of CSS tips are useful to everyone who writes CSS Web pages. One tip I think he's missing is to use a master style sheet so that you clear out all the different browser quirks.