I agree, always found I got nice smooth landing on the 321 by using a slightly flatter flare. On the 320 I make a nice positive flare, on the 321 still a positive flare but to a couple of degrees LESS nose up than the 320. I have done this since a training captain told me a really positive flare in the 321 results in you 'driving' the main gear onto the runway. But please don't mistake this as not flaring, I agree with the above, start the flare 5 seconds or so before you wood on the 320 and just maintain a slightly flatter picture out the window.
As for the thrust, don't be in a hurry to 'chop' the power, just a nice steady retardation starting at 30' until touchdown, if you chop it then watchout
Generally at light wieghts I start taking power off at 30', the heavier I get the later I leave the power, so if I am near MLW I don't touch the thrust leavers until well into the flare, passing through 20'.
Likewise, with a strong headwind I leave the power in slightly longer, with a tailwind I take the power back at 30'.
Thing is you just get a 'feeling' for this stuff. Still doesn't stop you getting a 'banger' of a landing every now and then
Experience will just mean that you go for longer periods between bad landings
