Think the sooner you can start using it the better, I just used ailerons for ages with the exception of slow rolls / knife edge but now I'm doing more and more 3D whilst I don't have to think about the sticking for ailerons I have to really concentrate with rudder input which you'll probably eventually want to use for inverted flight and turning in Harriers etc.
I'm sure in a while the rudder will just become second nature to me as well and I'm making myself use it for all turns now but if I'd started using it a year ago I'd probably be that much more advanced now !!!!!