Well, my father used to tell me if you could fish a plastic worm effectively and learn to detect the softest of strikes, then you could master anything in fishing. I personally love to fish plastic worms. Here is what I can tell you.

Colors
    Fish whatever color you have the most confidence in. My father used to say any color was good as long as it was purple with firetail. That was just his favorite, and I saw him catch hundreds of bass with it. Me, personally, I like the natural colors. I live on ultra clear Beaver Lake in Arkansas. I usually use colors like pumpkinseed, watermelon, motor oil, and black.

Conditions
    You can fish plastic worms anytime, but they excel whenever the bass are holding to some piece of cover or structure. For instance, you can flip and pitch worms under boat docks. You can fish them deep in brush piles or shallow near floating logs or bushes. You can fish them on grass lines, channel breaks, humps, and other forms of deep structure. The best thing about worms is you can fish them anywhere. I have caught bass in a foot of water and in 40 feet of water with worms.

Rigs
    I won't even attempt to go into every way to rig a plastic worm, but here are a few I like. I generally fish three rigs with worms: Carolina, Texas, and floating.

    The Texas rig is done by taking a plastic worm and an offset worm hook. It is important that the hook be offset. Take the point of the hook and poke it in the end of the worm. When you have about an 1/4th of an inch in the worm, poke the point of the hook out the bottom of the worm. Having done that, slide the hook all the way down through those two holes you just made. As you get to the top of the hook with the offset, twist the hook around so the point is facing towards the worm. Now you should have the offset in about an 1/4th inch of the worm and the hook point next to the worm. To figure out where to insert the hook point, hold the worm straight with the hook point next to the worm body. Where the bend in the hook meets the worm is where you want to insert the hook point. Insert the point and then make sure the worm is straight. You should put a bullet sinker on your line, then tie the line to the hook. It is important that the worm remains straight to keep it from twisting and turning unnaturally.

    The Carolina rig is basically a way to cover a lot of open water or deep water with a plastic worm. Basically, take a big sinker like a 1-oz or 3/4-oz egg sinker, feed it onto your line, then feed on a plastic bead, and then tie on a two way swivel. The bead will protect the knot from getting damaged by the big sinker. Then take your spool of fishing line and cut off a leader. You can use between 2 to 5 feet of leader. Attach the leader to the free end of the 2-way swivel. Finally, take your hook, attach it, and then Texas rig your worm on the hook.

    For the floating worm, take a straight worm and rig it Texas style. The only difference is rig it Texas style about 2/3 the way down on the worm, rather than at the end. This lets you twitch the worm and it not move very much. Rig it without a bullet sinker. It is a sight bait - learn to be a line watcher. Watch your line for slight jumps or for it moving in a direction other than the direction you are guiding it.

Techniques
    In the early spring, I fish worms in the cover in the shallows. I am generally flipping or pitching a Texas rigged worm. I am targeting areas that have bushes or logs that have collected along the bank due to heavy run off and rains. I also will Carolina rig worms and fish them along points at the mouth of creeks and areas that bass will stage in, waiting for the water to get to the right temperature in the backs of creeks, where they will spawn.

    In summer, I fish Carolina rigged worms on deep underwater structure and flip Texas rigged worms under boat docks. In the fall and winter I switch to different baits and don't fish worms much but that does not mean that they won't catch fish then.

Conclusion
    The best thing I can tell you is get out there and fish them. Learn to feel the difference between a rock and a clump of grass. Learn when you are butted up against something and when a bass is holding your worm. Learn to feel what the worm contacts and you will become a much better bass fisherman.