Best Practices - CSS Theming

Question

Quite often when I design a website for a customer, I design his website with one (or multiple) CSS files that makes up the entire presentation layer. The thing is, usually, the

Answer 1

Consider the approach suggested by OOCSS. The general idea is to separate the style concerns of your classes into more granular units, so that you end up using more classes in your markup instead of hanging all of your styling on too few classes with overlapping concerns.

This can be combined with some of the other suggestions. (I highly recommend authoring SASS with Compass!)