I have my favorite spring creek I fish about 80% of my total trips each year. Two things: wade quietly and very slowly - sight fishing works if they don't see or sense you first. Present your nymph at the depth exactly where they are holding - I use a Parasol Emerger and drop two nymphs, with the first a bead-head measured to the depth of the holding water, trailed by a smaller unweighted offering (usually one of my special spring creek scuds in size # 14). It works great.

This is a picture of a typical fish from my favorite spring creek and the water I fish in the background:



Another great fish from the same water:



A great shot of the water last year:



Anyway, good luck.