The best practice is … don’t slice PSDs and convert them to HTML/CSS. Create a web page, don’t draw a pretty picture. See a previous discussion for what we said last time this question was asked!
Also could image map the actual image but that would be a pain in the butt hehe
I see people wanting psd to html sites a lot, I guess they’re unfamiliar with good practice, usually they’re designers/graphics people, if they’re willing to pay money it might be worthwhile.