Pedal like a bastard and pull the stick into your belly as soon as you touch down (in a three-point landing), and pedal like a bastard. Tap-tap, tap-tap on the pedals. Don't put in a bootfull of rudder and then leave it there or you'll just create the opposite problem to what you had; put it in and then take it off. Tap-tap, tap-tap.
Don't let it get away from you, sort out any deviations immediately, be quick and sharp on the pedals. I always reckon that a pilot has got the hang of tail draggers when he knows what the aeroplane is about to do and stops it before it does it.
In the air you just need to get used to co-ordinating turns with some rudder, the differences are all on the ground. It's not magic, and it's not the stuff of supermen. Stay both relaxed and alert and just make sure you enjoy yourself.