I've only been fly fishing for trout for just under 2 years, so I'm not an expert. Not sure what a buzzer is either. But as far as nymphs and shrimp (the shrimp patterns I get are called scuds), you basically let them drift with the current. It is important that you get them down to the depths that the trout are feeding. Use some small pinch on weights and experiment to see how quickly the nymph sinks. I place the weight at least 8 inches above the fly so that the fly still drifts naturally. Also, use a strike indicator placed far enough above the weights that the fly can sink to the proper depth. When I started, I liked to use 2 or 3 pinch on strike indicators placed several inches apart so that you can watch for sudden changes relative to each other. Sometimes trout strike so subtle that they won't pull the indicator under. They can spit out the fly quicker than they took it, so be ready.
The real trick with dead drifting (including dry flies, too) is getting a natural drift. If the current pulls your line faster than the fly should be moving, most trout will realize something is not right. Watch your strike indicator to get an idea. If it is moving differently than the bubbles and debris around it, than your fly is probably not drifting naturally (of course there are under currents as well which make it more difficult). The easiest method is to cast straight upstream. Eventually you'll learn how to "mend" your line when casting across stream. Mending allows some time for the current to drag your line before it drags the fly.
Often I use 2 nymphs at a time. You can either leave an extra long tag end off your knott for the 2nd nymph, or you can tye on a separate piece of monofiliament to the bend of the 1st nymph. The only problem is that 2 nymphs tend to get tangled much easier if your cast is not made properly.
I hope this helps. As I am still somewhat of a beginner, I hope others may feel free to correct me if needed.