The keys to a good landing in a conventional (non tailwheel) training aircraft ...
1) You HAVE to be on speed. All the landing advice from all of us experienced guys here will count for nothing if you are 10 kts too slow or 15 too fast at the roundout, the best technique in the world will turn to ****.
2) You have to round out at the correct height, a lot of bad landings come from rounding out too high, this is normally caused by the pilot getting ground rush from flicking their eyes around between the instrument panel / runway threshold in the close in approach when they should have been following my next tip which is the real key to the whole thing
3) LOOK OUT THE WINDOW at the HORIZON! From my thousands of instructing hours, whenever someone had an awful landing it was always the case that their focus point was closer in, they were looking at the touchdown zone, I know it's human nature to look there but it's impossible to accurately judge sink rate unless you are looking at the horizon. I know your instructor has probably told you that 1000 times already, but ask yourself honestly next time you crunch one onto the runway, where were my eyes looking at that moment? All pilots, even the most experienced ones, still do it occasionally because we are still guilty of lapses. Particularly if you have been distracted by being a little left or right of centreline, you still have to force yourself to look back up to the horizon in the roundout & flare.
As long as you have carried the correct speed and roundout height into the flare phase then it's almost absurdly easy to apply the last tiny bit of back pressure and clear that nose wheel for a nice greasy landing.