The 15mm Wargaming blog has a nice little article on how he adapts individually based figures to DBA style element basing.
I find it interesting because I do a similar thing myself. All of my ancient and medieval figures are individually based so that I can use them in various skirmish games. However, I also have some magnetic “movement trays” that I stick them on for element-based games (mostly Might of Arms). My cardboard and magnetic vinyl bases, however, don’t look nearly as good as the ones in this article. I base mine on 1 inch washers, though, so I will have to investigate to see what similar things are out there for that size.