The only thing that I can recommend is to use a good flourocarbon line. It makes all the difference in the world with jigs. Where are you fishing at anyways? If you're down here in So. Cal. I might be able to help you, but the boys up North won't steer you wrong. Color can be unimportant or everything. When I fished up in Oregon for small mouth they wanted colors that matched the crawdads. It just happened that the guy I was fishing with pours and ties his own. They were spot on and we caught a ton of fish. Bigger trailers slow your fall, but sometimes they draw more strikes.

Dirty water-definately black or combos of black, like black and blue etc;maybe add a rattle? Heavier for flipping like 1/2-1 1/2

Clear water-Greens and browns, maybe smaller sizes like 3/8 or even 1/4. I've had great success with 1/4 ounce jigs.

Jig head shapes can make a difference too, like football head or sled type head.
So good luck and be patient, the more you fish it the more chances you'll have to stick fish on it.