Well said StiknRuda
I was flying with a friend who as we turned finals, looked down at the altimeter, read the value and said '600 - that's OK'. The fact that we were x miles out and low on the approach seemed to have escaped him.
I was always taught to fly the circuit looking the the relative angles to the landing point - something to do with being trained in gliders, I think. In fact, once established on the downwind leg, I rarely look at the altimeter again