The first and most common mistake that most of the players make is to try and bluff their way through by going in for a small pot. Secondly, if you have made an online poker pot size bet that is on the larger side, you should try and do everything that is within your control to try and win the pot. Furthermore, you should try and control the size of the pot which will go a long way in confusing your opponents and make them commit very rudimentary and simple mistakes.
However, the job of defining and deciding the size of the pot does not come overnight and there has to be a lot of hard work and practice before one can really master it. The best way to master the size of the pot would be to go with a number of games with your friends who have the requisite experience and expertise in the mater. You are bound to make mistakes but you should not worry about them. You should try and learn from the mistakes and try not to repeat the same. It comes with experience and you should be prepared to play the waiting game.