When I first started doing web development, CSS was by far my weakest skill. More concerned with reducing tasks that would normally take an engineer hours of time to do manually into tasks that a web-server could do in mere seconds, the appearance of many of the applications I wrote was downright pathetic. The applications still saved the company thousands to millions of dollars though, which is really all i cared about at the time.
After leaving Texas Instruments, I quickly found out that selling apps that didn’t look very good to relative strangers was much more difficult that it was selling apps to a bunch of engineers that already understood what the tools would buy them. And so, I forced myself to spend some time concentrating on this paradigm, and eventually became quite competent with regards to the skill.
Now, although I don’t have all the latest CSS 2 & 3 constructs committed to memory, I can do front-end UI development with the best of them. When applicable, I utilize the latest CSS frameworks such as 960 grid system and YUI, and I always employ the most favorable practices such as table-less design. This allows me to easily guarantee that “PSD-to-ANY” conversions are pixel perfect and that the interfaces I design will are cross-browser compatible, no longer having to rely on the old addage that “Friends don’t let Friends user IE”.