Here's a simple Czech nymph pattern I tied for the January 2013 swap. I call it the Krystal Czech nymph as the Krystal dubbing I used adds a bit more flash.
Hook: Daiichi #12 wide gape scud hook
Thread: Uni 8/0 black
Underbody: lead tape
Back: 1/8" Sow-Scud back, clear
Abdomen: Krystal dub dark hare's ear
Adbomen rib: Uni-French Silver oval tinsel, small
Thorax: band of Angora goat burnt orange dubbing and band of Krystal dub black
Ribbing: 2x mono wrapped over whole fly for segmentation
Drop of Sally Hansen's Hard As Nails on top of thorax.
1. wrap a thin strip of tape over hook shank
2. wrap second layer, starting a bit higher than starting point of first, and ending a touch earlier.
3. lay down a thread base over tape then tie in the mono then the scud back, followed by the tinsel.
4. dub the abdomen and wrap the tinsel over it creating ribbing, tie the tinsel off at the end of the abdomen.
5. dub the burnt orange followed by the black segments of the thorax
6. pull the scud-back over the back of the fly tie it off. Then wrap the mono over the fly, trying to follow the tinsel on the abdomen, to create segmentation. Whip finish and cut your thread.
7. Use a dubbing brush/pick/velcro to tease out the dubbing from the thorax to create a buggy effect on the bottom of the fly. Apply a drop of Sally Hansen's to the top of the thorax. I use my finger to be sure it gets on the head and a bit down the back.
There you have it! Hopefully it'll help you get your smaller nymphs down deep and also catch you a few fish.