Jigs and soft plastics are definitely some of the best fish catching baits ever made and are an essential piece to every angler's tackle box. Here's our best answers to each of your questions, but always remember that nothing in bass fishing is always going to hold true. Even the best of techniques and patterns sometimes fall through.
1. There are two colors, green pumpkin and black/blue, that you always need to have handy. Opt for green pumpkin in clearer water and throw dark colors like black and blue in dirty water conditions.
2. The amount of movement you should put into your jigs and soft plastics depends on the state that the fish are in. If fish are actively feeding, more movement can trigger more strikes. If fish are lethargic, dragging your bait along the bottom with little movement is the best option.
3. Choosing a natural bait is all about "matching the hatch." To match the hatch, you need to throw a lure that imitates the forage that the fish are feeding on. For example, if bass are feeding on craw fish then a jig or soft plastic craw would be a good way to match the forage.
Bait color plays a huge role in creating a natural presentation that imitates forage. It may not be perfect, but do your best to fish a lure that resembles the color of the main forage. A common example of this is using a silver and white crank bait to resemble shad, a common bait fish.
Happy Fishing!