Sunfish,
you need to anticipate other traffic. Speed up a bit in the circuit if the plane behind you is a bit close, slow down (or go a bit wider) if the one in front is too close.
The tower controllers there are very good and friendly. They are used to having to deal with a busy circuit full of low time students. The controllers do a great job of moving a lot of traffic efficiently.
If the circuit is really busy sometimes controllers will move traffic to the western side of the circuit.
The only times I've had to go around have been when I've been impatient and cut the circuit a bit close.