A good maxim to follow when fishing bait in rivers, streams, and creeks is to use only weight to get the proper cast and drift. This is very important. Too much weight results in either the bait snagging on the bottom or having the natural drift inhibited. Again, if you can get by typing directly to 2 to 4 pound test line, this will help to minimize any drag, that you would otherwise get from a swivel used as a leader link.
The simplest technique with bait fishing a stream is to not use any weight at all. By leaving the bail of your spinning reel open following a mid or upstream cast, the bait can naturally cascade downstream. Since the monofilament weighs practically nothing combined with bait, it will take some practice making even the shortest casts with this method. You may also have to help pay the line out by hand, at least initially, until the current starts to sweep the bait downstream.
Occasionally, throwing downstream then skittering the bait upstream across the surface can also work. Bigger, more aggressive and hungry rainbows and browns will sometimes strike the bait fished this way. It is as if the trout sense that a tasty morsel is quickly escaping upstream. If the weightless tactic doesn’t seem to keep the bait properly in the drift (especially true in very swift flows) then add a small BB shot about 18 inches above the hook. This minuscule weight will surprisingly add quite a bit of casting distance, particularly in the wind.
Use large split shot as needed depending upon the distance and or depth necessary to keep the bait in the strike zone. Here is another tip: buy the old fashioned split-shot that has to be crimped on with pliers. The more recent innovative style has protruding ears that allow you to pinch the shot by hand. This type of lead is convenient because it is removable but the little lead ears have a greater tendency to get hung up than the simple, rounded variety.
For faster, more turbulent water, particularly on larger streams and rivers, some anglers prefer to bait fish with a sliding egg sinker. Use the technique described for fishing a basic bait rig when still fishing in lakes. However, for rivers and streams, use the sliding sinkers in much smaller weights, usually under 1/4 ounce.