Avoiding getting blocked has to do with a number of factors. It can be tough to diagnose your problem without seeing how
you're getting blocked but typically, outside of disproportionate size, age, and weight differences, here are some ways to avoid the block:
1) Use your body as a shield:
I think this is the most important tip. I teach it to my players by having them drive baseline without any defense. Many players will inevitably drive that baseline facing the rim the entire way. They'll jump and attempt a layup, again, with their feet pointed at the rim.
Next, I'll place a dummy defender at the rim, standing with his arms straight up, then I'll have my players attack in the same manner. What happens to those trying to finish a layup from the baseline with their feet pointed directly at the basket? Well, there's no barrier between the ball and the defender's hands. If that defender jumps at all (or not) it's often an easy block.
To make my point, I'll then have my players drive and square their feet to the backboard before rising, thus placing their entire body between the ball and their defender. I'll have that defender actively attempt to block the shot, at which point they'll either commit a foul and fail, or still complete the block, but often while fouling or through a great effort. Either way, the point becomes clear. Correctly using one's body (from anywhere on the court, not just on baseline drives) can often neutralize many physical advantages the defender may have to begin with. Here's another example of how the correct placement of body can assist: http://www.youtube.com/watch?v=qbITKv5OEkQ#t=3m47s
. I say experiment with the flow of your game and how you can effectively use your body without overdoing it (i.e. don't blatantly lower shoulder and clear).
2. Use Correct Shot for Situation:
I have two little brothers, aged 16 and 14. The 14 year old is routinely dominated by the 16 year old, largely because on his forays to the basket, he attacks with little speed and attempts shots that do not fit the situation. For instance, from the right wing he'll attack with a lefty dribble, then attempt to finish with his right hand, more or less shooting it directly into his defender's arms.
To tie into the previous tip, many of his poor shot types tend to work out so poorly due to the lack of body contact usage prior to his shot. Often, he'll attack looking to avoid his defender by all means possible, which then allows the defender to dictate a lot of the action. My littlest brother will drive to a spot, only to have that space already covered, where he'll either be blocked, or slowly pump fake, think, then get blocked.
3. Don't Fear Your Defender:
Again tying into the last tip, avoiding contact by all means is doing the defender a favor. It's allowing them to come toward you however they see fit. However, if the offensive player dictates the play by going at their defender (instead of trying to stay entirely away from them), the offensive player has much better control of the situation. Many shot blockers thrive off of the empty space between themselves and the offensive player. It allows them to build up their spring and attack the shot. Again, an offensive player who's able to become adept at knowing how and when to create contact (without sacrificing the ability to make the shot) will have a much lower chance of being rejected.
4. Decisive Moves, Decisive Pump-Fakes:
If used correctly, one-on-one is a great vehicle for developing new fakes, moves, and finishes. Instead of attempting the same old tried-and-true moves (or tried-and-fail), be open to thinking of new ways to elude your defender, and try them out. Pump fake when you know your brother is sure he's got a block. Drive strong when you know he's right on your tail, then give him a Rondo pump fake at the rim (http://www.youtube.com/watch?v=rJEbbS1wY0Y)
Experiment, but whatever you do, do it at full speed. There's not a whole lot of things worse than that moment in one-on-one where you pick up your dribble, realize the defender has you closed out, then you pump-fake half heartedly a few times before throwing a wild fallaway. If you fake, or if you lose your dribble, make a definitive counter move.