As a beginer at fishing nymphs, use a strike indicator placed at one and a half
times the depth of the water. Put a split shot about six inches in front of
the nymph. Fish the strike indicator like a dry fly. Adjust your casting
stroke to throw wide loops; more of a slinging action than the hammer motion
associated with dry fly fishing. You fish a lot closer than dry fly fishing
and get a lot more tangles as the strike indicator, split shot, rod tip, and
fly tangle. You should get an occasional snag on the bottom. If not, fish
deeper by adjusting split shot weight or distance between the bobber and fly.
Not getting the occasional snag or periodic bumping on the bottom means you
are not fishing deep enough. Strike quick, but not like a spin casting bass
fisherman. Remember you only have to move that hook point a fraction of an
inch for penetration. Many fish will mouth and spit out a fly quickly.

Lou T