Stik mentions about flicking left and right. Once you are happy with the technique, I would recommend always practising both ways so you don't become handed. Apart from the satisfaction of being able to do it properly, this can become particularly important if you are involved with competitions or displaying flying. The flick will displace the aircraft laterally and can have a marked effect on the positioning of the aircraft - so if you can flick both ways you can clearly use this to your advantage!
TAC