The thing that really stuck for me when I was first getting my licence was to flare 'when you feel the runway come up round your ears'. In other words, when it no longer looks flat from above, but has a feeling of enveloping the aircraft.
Works for me mostly, although flying almost exclusively out of small, narrow, short grass strips I now have a lot more trouble pulling off a decent landing on acres of concrete (ugh, revolting stuff!).
Anyway, ignore what I say and listen to Chuck because I am, and let's be honest about this, a low-time ignoramus with an unwarrantably large mouth.
QDM