The best tip I have received as a new teacher are behavior incentive slips. I give students a slip where they write their name and have drawings every Friday -- if they are chosen, they get to pick a prize which range from no weekly reading log to listening to music during DEAR or even eating lunch in my room.
My 7th graders love the variety of prizes -- while some HATE that eating lunch with me is a prize, others are like "I'm going to win this Friday and come eat with you!" So there really is something for everyone and you can always add. I don't spend any money on the prizes.
PDF and PPTx of Jar of Wonder + Prizes: I print this and place it around the ticket jar so students can peruse the list at any time
PDF and PPTx of You Rock slips: I print these on three different colored papers so each class is a different color, you could also have three different jars.
(If editing in Powerpoint, you MUST downloaded the included fonts and add them to your font list)