[findm]

I think alot of it depends what it is that you are building. My approach to would be different if it were building a large scale web app vs a website and it also depends on the team thats helping to maintain it (ie. if it were to be maintained by engineers who don't really know or care for css or a team of web devs)

I always start off with a base which consists of the misc. browser fixes and hacks + basic typography elements, rough blocking. My philosophy on formatting really follows what everyone here is saying. I really prefer horizontal lines and proper tabbing of all the sub elements because its really hard to read otherwise.

While commenting is really good and I like it, finding the proper balance is the key. When you're doing fast iteration it gets really tedious and cumbersome to go back and make sure your comments are in sync.

This is how i arrange my css: http://maderogue.com/public/assets/css/base.css

For bigger project I like to break things down by specific functions & models. (ie. tables, buttons, sorting controls, etc.)

i really like the way jquery ui themes are done.