Its easy...
You just need to set the correct attitude, at the correct height, at the correct speed, with the correct power (probably idle) and don't let the nose drop / pitch forward at any point...
Don't worry - at some stage it will just click! It is all about judgement, which is something that everyone needs to learn for themselves (I've had my licence since April and lets just say, some of my landings still have a lot to be desired...).
A stable approach at the correct speed / angle helps enormously. Ideally on approach you should be stable and trimmed enough and that you can take hands off and nothing changes.
I'd also try to keep the same instructor for a spell. There are sooo many different techniques (to get the correct attitude for example) and everyone has a favourite but you really only need to master one of them, so it is easy to get confused with differing instructors.
Enjoy your training!
RR