deffo charge whilst training, after my first course, i was doing sets for free on two friends, and they were always popping off , lifting and not lasting , i thought i was crap, but then i took my next course and i found that if i charged £10 (that was all), they managed to keep their nails on, and wanted rebalances too, i think its sooo true if you give them it free, they dont look after it, but if they've paid out, no matter how little, they think "well its my hard earned money i'll look after them"
plus, you have to recoup some of your costs hun, otherwise you'll have no money to buy new stock etc
hths chick xxxxx
oh and also, if your dsoing them for free, it almost gives the impression that you dont think your worthy of charging, whereas doing them at a reduce rate, makes people think, your good enough to charge, but you know you cant yet charge full price whilst your training, so gives them confidence in you iykwim? x