Have a look at this technique for nymphing to get your fly to drift naturally and provoke a strike from those trout.
Reds Fly demonstrates a great technique for nymphing that you will definitely want for adopt for those trout streams and rivers this spring and summer.
There you go: a simple, but often overlooked technique that is going to drastically improve your success rate by providing a much more natural drift to that fly. While mending your drift by shifting the rod horizontally works great for dry flies, it almost immediately gives an unnatural look to your nymph fly by causing tension and breaking its natural drift with the current.
Do overhand mending to keep a slack line and get the best out of each drift. This technique for nymphing is something I am going to definitely try on my home waters this season, it should work well for trout and other freshwater species alike.
For some great nymph patterns to add to your fly box be sure to check out the variety available from Orvis.