I agree Lisa- so no m & ms in my house. What we do it play time after school. dinner. homework and then the reward when hw is done is play a game or watch a show, the books & cuddle time. We definitely have nights my 2nd grader doesn't want to do her homework and you know what I don't feel like having her do it either. So for now I sit with her on those nights and offer moral support and try to keep her on task. Works most of the time.
Any incentive with points, stickers, marbles, is great - but make the reward fairly easily attainable - for example; 1 sticker each day for doing homework - 5 stickers = trip to the ice cream store/park/playdate on the weekend. (Not advocating all food rewards, just using an example :-)