I think theme framework like thematic are very complex to work with. You have to spend some time with them to know how exactly they work, and how’s generated markup look like. So, I’ve made myself a blank theme. I’m familiar with my own code conventions so I like it more than thematic.
Granted I’m new to WordPress, but I’ve been developing a ton of custom themes just to get a handle on it. What I’ve settled on is getting Starkers and I’ve created several basic blank layouts from Starkers and then saving those separately.
I made a basic left side nav, right side nav, content in the middle. Then I made a classic header, then horizonal menu, then content area template. Then I created a couple variations of floating side navs with horizontal or vertical menus.
Now I have those in a "theme" folder (not inside WP) – when I practice to get better, I’ll go to any template site, look around for something appealing, then I’ll try to duplicate the overall feel. Then I’ll take the template that has the basic elements I’m seeing, copy that into the themes directory and I can literally start manipulating it immediately, inserting graphics, changing widths and heights, etc. Because I’ve already laid the groundwork for the basic styles, I can quickly find what I want and start changing it.
Now, I just need to learn alot of the WP tips and tricks :)