It will come with time my friend, just keep trying, everything will come into place and within no time you'll have the balance of a balanced thing! Practice practice practice, seriously, it's the only way you're going to learn things. BUT, if you aren't a novice and have a decent balance, it might be that something on your bike is wonky, such as your bars, they might be to one side or something similar, which will cause dodgyness, try making things that go side to side (mainly bars, grips and levers) all as symetrical as you can, even the smallest things really can make a big difference.