Two Way Shots
One of the things that separates the pros from the amateurs is something called the two way shot. The premise of a two way shot is that you can go for the win while managing your down side. To the unskilled eye many of these 'misses' look like luck, but great players, when they finally miss, usually miss the same way, and that way usually isn't good for the incoming player.
One of the most common two way shots that you'll see is on the game ball. Sometimes you're left with a cut across the short rail. Good players usually try to cut the ball in, but hit it soft enough that it comes back to the center of the end rail on a miss, while the cue ball goes to the other end of the table. Every now and then your opponent will long bank this one in, but at least you made him earn it.
Another great two way shot is when the cue ball and object ball are on opposite long rails below the side. If the bank in the side is 90% or better then go for it, but if there's a slight bit of doubt you can play a two way bank to the corner. The cue ball should go up table, and if you don't make the bank, the speed should only take it back to the center of the short rail.
Another form of two way shot is when you're shooting a long, tough game ball. If I have a long shot into the corner, I will usually follow the cue ball up to freeze it on the rail. The miss will most likely leave a bank or a very tough shot. Sometimes on a shot like that I will cross bank the ball (with speed to send it back to the center of the end rail on a miss) and send the cue ball to the opposite side of the table. If you really hate long tough shots this may be a great option for you.
Most people hit the balls way too hard, so you may have to practice hitting these shots at a slower speed until you get it. The more you try them the more often they start going in. Some people say two way shots are aiming to miss, but I disagree. The only change that needs to be made is a speed adjustment so that a miss will send the ball to the center of the end rail and not right in front of the pocket. Giving yourself that extra chance to avert disaster is just smart pool, and I've found that the more down side protection there is, the less pressure I feel, and the more likely I am to make the shot anyway.