Hierarchical grid comes next. And some proper design chops, maybe.
In the spirit of getting it out there, I've now begun implementing a columnar grid system on my site. As discussed in Mark Boulton's excellent talk at DrupalCon Paris 2009, and reported briefly in my live notes from the conference. such grid systems are a basic underpinning of consistency and visual clarity on a site. You start at the grid, then decide how your actual page elements are going to fit into it.