Keep Lines Separate
Pull your line and jig out of the water if a fishing companion has a fish on their line. Not only is it common courtesy, but it avoids the risk of lines crossing, getting cut, and losing not only a fish, but your jig as well.
Keep Jigs Close, Dry
Hook your jigs onto a fly fishing hat or vest, making them accessible when you are in the water and out of the water. You should dry off your jigs after use to slow rusting and deterioration.
Mimic Water Creatures
The jigs you use should impersonate wildlife found in the waters you fish. Using a prawn-styled jig in a stream where prawns do not live will not be successful because fish will not recognize the jig as prey. You should research and educate yourself on the kinds of food available to and popular among the fish you are trying to catch and use the appropriate jigs.
Know the size, or typical size, of the fish you are trying to catch. Using a jig that's too large will reduce the fish available to catch. If in doubt, use a smaller jig, but if you are going after mantle-worthy catches, go big.