I would mark the poles that represent 1/4, 1/2, and 3/4 points on the circuit. Everytime you have a problem on that circuit, go to the pole that represents the halfway point on the circuit, and break the joints. Go turn the breaker on. If the circuit breaker trips, you know the problem is on the first half of the circuit. If it doesn't, you know that the problem is on the second half. Remake the joints at the halfway point, and go to either the 1/4, or 3/4 point, and start the process over again.
This is know as "half splitting".
The Watt Doctor