It also a good idea to get back to basics and learn to flare via visual references, instead of reliance on RAD ALT calls. There is some very good reference material on the following website.
The Jacobson Flare
It basically states that for each aircraft type there is a specific aim point which will have you crossing the threshold at the correct altitude. There is a also a specific cutoff point on the runway which is the cue to commence the flare, this will put you at the correct flare height. For example on the A330 aim point is about 1150 ft from the threshold (end of the 1000 ft markers) and the cutoff point is approximately the end of the 500 ft markers. So you drill your aim point maintaining a 3 deg approach and as the 500ft markers start to slip beneath your view below the combing commence the flare.