I have yet to code a WordPress theme from scratch. I have found something I like and started from there. For the MacDolphins web site, I had found something simple a while back and it served it’s intended purpose but it wasn’t without issues.
As the site has grown, the need to tweak the side bar in particular has increased. I found an extension to FireFox called FireBug which has made this process significantly easier. I am using FireBug to chase down CSS conflicts and oddities but it does much more than I realized.
My theme now works correctly even if it isn’t visually very exciting. The mouse overs no longer overflow the sidebar for 3rd and 4th level deep menus. I was able to resize the sidebar and the overall content area without things ending up in the wrong spot. If you dink with themes, FireBug is really helpful.