The importance of keeping a good connection to your fly (or flies) is critical when nymphing.  Here I describe some quick do's and dont's for tandem rig nymphing.

Also check out this article on nymphing

The first cast made on a small stream will usually be the most productive - if you choose your spot carefully.

Trout want two main things in life; food and shelter.

Getting them both in the same place is ideal. In the photos below I mark shelter-only or food-only spots in yellow. The red (hot spots) have both.

I am certainly not an expert, but I have spoken to many of them, read their books and attended the occasional seminar.  What I have put down here is my top 5 list of things that have helped me.  If you too are trying to learn the art - I hope this helps.

Tandem Nymph Rigging - Nymphing for Beginners

Since it's refined to include only the methods that seem beginner specific (based on my newbie-ness), it's almost
impossible to give credit to those who probably deserve it.

Certainly Ed Engle, Jim Reid and Dave Whitlock inspired me in their own ways.

Since we all know that spooked fish will never take a fly, here are some tips for making sure you can sneak up on ‘em.

1) Don’t rip the water on pick-up.
2) Walk lightly – don’t stomp near the shore.
3) Avoid casting shadows on the water.
4) Gently present your fly to the water surface.
5) Release fish heading away from your fishing hole.  Much like a cattle stampede, spooked fish spook others.
6) Cast upstream and a bit to either side of your target.  They will not see or smell you (if you’re wading).
7) Sometimes a short break to let the pool settle is worth it.
8) Keep in mind that a trout can hear an insect strike the surface, so every splash and plunk is noticed.

Leader and Tippet Length

I just left my favorite lake 3 hours ago and had to post this up right away.  This is exactly the type of experience that I wanted to share with other beginners - hopefully this is helpful to someone.

Starting out this afternoon with a 9' leader, about 12" of tippet and a stimulator, I stood near a boat dock casting toward the shadows.  It didn't take more than 2 or 3 casts and I could see that the fish were plentiful and interested.  I worked the stimulator, got a hit or two, but became convinced that the size 8 hook was too much.  I cut the tippet, tied on a small (maybe #14) fly.  Got no interest.  Ok, so they wanted something more "buggy"... well I forgot my main fly box, and only had a small variety of fairly disappointing flies.  I tied on fly after fly, exhausting the tippet, then eating into the leader.  No biggie, it was still pretty long.