I use the technique some, for small trout and bluegill. I usually put my casting bubble 12" or 18" above my fly. Locally, bluegill hit ants, any type of midge pattern and copper johns. I make black foam ants with supplies I get from Netcraft. We also have a bunch of cheap flies that come in an assortment pack from South Bend that we bought at KMart. The gills tear them up pretty fast and it's easier to buy them for me (with my limited skills) than to tie them..
I've also picked up small LM bass on wooly buggers.
Something else we do if the trout or gills are surface feeding, is just put an unweighted hook with a waxworms on the line where it drifts just below the surface behind the bubble - Roberta.
"Anglers are born honest,
but they get over it." - Ed Zern