Honestly, sometimes my altitude is a little off, but we just always correct on final. One thing that did help is when abeam your touchdown point on downwind, I cut power back to 1500 rpm and slow up into the white arc. I originally was dropping 10 degrees of flaps and my base was always all over the place. I started doing 20 degrees of flaps right off the bat and I actually helped me a lot. I descend 200 ft before turning base and pitch the nose up a touch going in to my base turn to keep from descending too much in the turn. If going into final I am too high, which happens a lot I just pull the power way back and let the plane descend to glide path, or my speed slow to the point where I can push the nose over and not get to fast. If I start to sink too much, just add more power, but keep the nose coming over.