Students who struggle with their landings are invariably looking in the wrong place prior to the round out point. Sounds like you've been told correctly how to fly the approach because you say its going wrong below 50ft.
Fact is, where you look during the approach needs to change below 50ft, typically about rooftop height (30ftish) thats the point where you need to stop looking at the aiming point, instead look well down the runway before starting the flare (your peripheral vision plays an important role at this stage). You need to slow down the descent rate and that's done by reducing power slowly and raising the nose such that the approach becomes flatter BUT keep looking well ahead of the aircraft and all the way down the runway.
Remember its your peripheral picture thats helping you during the flare. The runway edge markings which were below shoulder height (from a peripheral vision perspective) when you changed your lookout to the furthest end of the runway, and the edge markings come up to meet your ears (again from a peripheral viewpoint - don't actually look to the side, just keep looking well ahead) and as this is happening keep gently checking backwards on the control column to arrest the sink rate, do it progressively whilst taking all of the power off until the aircraft can no longer fly and sinks gently onto the runway.
The secret ALWAYS is to keep looking well ahead but be aware of the runway edge perspective using your side vision!
Last edited by sapco2; 16th April 2013 at 08:33.