My preferred method of fly fishing for trout is to use a team of two nymphs dangling on droppers under a dry fly which I use as a strike indicator. This method is known as the New Zealand style of nymph fly fishing by some. I had been using this set up for years and knew it as the team of three before I was told that it had a name. My choice of dry fly will depend on the water conditions. If the river is rough then I will use a very buoyant fly like a Wulff or Adams indispensable. In calmer conditions I like to use a parachute dry fly or a Klinkhammer. The white post on these flies helps with visibility. Always apply floatant to the dry fly to keep it from getting waterlogged and sinking.
If you call the fishing with a bubble and dry flies fly fishing, then Czech Nymphing is fly fishing, too. If you are of the opinion fly fishing is done with a fly line that is used to carry your fly, nymph or streamer to your target then it is not. As weighted alibi flies(the hook melted into in the drop like end weight is far too small to catch fish) up to 10 g(!) and more were and are still used for Czech Nymphing in special situations it is obvious that it is completely impossible to make any overhead false casts with them (at least not with a proper technique and class 3-6 grayling rods). Quite often you see these Czech Nymphers even fishing only with long leaders maybe using a meter of fly line out of the rod tip, somethimes even less.