The best method I used is a main line coming down to a barrel swivel, tied to a leader which in turn it is tied to a jig. At the swivel, connect it with a float. If necessary, you can hang a split-shot or two between the swivel and jig to get the jig down and keep it at the desired depth. The depth of the jig is also adjustable by adjusting the position of the float on the mainline. Jigs come in all designs, materials and colors.
Floats also come in different materials, designs and configurations.
You should experiment with various colors and sizes of jigs. The main thing is to ensure that the size or weight of the jig does not drag the float down into the water. The float should act as a strike indicator as well as give the jig buoyancy in order for the jig to move naturally through a drift. If your float is moving ahead of your jig you need to adjust it so that the jig is drifting ahead of the float. If you get a strike, your float will rise up in the upright position before it goes under.