Mommy to Mommy

As my kids get older it seems like I am always having to re-evaluate how things are done at our house. Currently the girls are 5 and 3 and I feel like it's time to start a chore/reward system but I don't know where to start, especially with their ages. I few of the things I would like them to take more responsibility for are: cleaning (as in to the best a child their age can do) their bedroom and toy room and taking laundry to their room and bringing it to the laundry room. These are chores I know they are capable of doing so that's why I'd like to start here. Here's my dilemma...I don't know how to reward them. I know you would by now I would have that part figured out but honestly I don't. I'm not sure if I should do stickers, marbles, or money. If stickers, how many until they get a reward? If marbles, how big of a jar to fill up? If money, how much? What if they don't do their chore(s), do they simply not get the reward or do I take whatever I choose (again~sticker, marbles, money) away? Mommies I need your HELP, what has worked for you? What did you try that maybe didn't work?