Using rewards is simple in theory. A pupil behaves well, you reward them (as outlined in your behaviour policy), and this encourages them to repeat the behaviour. But if your school policy asks you to offer merits to Year 9 ("No thanks, Miss"), you'll have to cheat a bit.
Work out what motivates your pupils and use it judiciously: a smile from Sir, a chocolate bar, listening to music, a phone call home. Unusual rewards work a treat. Offer a "get out of homework free" card or place a padlocked treasure chest on your desk.
Change your reward systems regularly to keep them fresh. Begin with a "pupil of the week" award, move on to marbles in a jar, then top off the term with a raffle. Don't scatter-gun rewards about the currency loses its value. Offer one postcard home, or three really hard-to-earn merits. That way, winning is precious.
There may be something inherently dodgy about bribing pupils to learn and behave. But material rewards often stand for something more complex and long lasting: "I'm pleased with you, I like what you've done, you're a success." And the approval of someone they respect is the most beautiful reward of all.
Sue Cowley is an educational author, trainer and presenter. Her books include Guerilla Guide to Teaching (Continuum). For details see: www.suecowley.co.uk