I do a lot of flyrodding for largemouth and smallmouth. For a "popper" the fly I use for both is the same; a cork one that I make with a 9/16" face, tied about 3 1/2- 4" long. The color doesn't matter much, but I often use one with an orange head and a black tail. When largemouth are in heavy cover (pads) I like a version of a Dahlberg diver that I tie upside down on a 4/0 Daiichi 2481. The collar on the fly acts as a great weed guard. I usually use a long, wide rabbit strip for the tail on this fly. For high riding subsurface, I use Deceivers (mostly natural colors) and rabbit strip muddlers in natural or black. Tie both about 4" long. For bottom bouncing, I have a couple of things with lead eyes that I use. One is a lead eye zonker (white or brown), and the other is a "clousery" thing tied with extra select craft hair instead of bucktail.
I made a couple of DVDs on Largemouth fishing and tying last year. They are titled "Flyfishing for Largemouth Bass, Vol. 1" and "Fly Tying for Largemouth Bass". The tying DVD shows how to make cork poppers and inverted divers. The distribution on them isn't great, but if you look hard you can find them.