I'm kind of back and forth on this...
I really don't all that much as far as school or chores... it's kind of just what they are to do. They dont expect a reward.
However, there's generally SOME kind of reward in adult life. My DH works hard and he gets to keep his job and get a raise when it's time. He slacks off and he loses his job no longer getting a paycheck. He literally only goes to work because he gets paid for it. (he loves his job, and does the same thing when he's home, but if he had to choose between going to work or staying here with us, he'd pick here.) I do my job well and my kids "pass" their testing, the house is cleaner, we eat, and my dh is way more likely to happily let me go out with friends on Friday night
My kids.... the only thing I suppose they get on a regular basis for doing their jobs well is to be kids. I mean, we'll praise them if they've done something above their level (like when my 4.5yo did laundry all by herself for the first time!!)
Now, we do have basically 6-8 weeks of their regular guides and then 3 weeks where we do DITHOR and catch up or get ahead with math/English/dictation. Those are really easy three weeks where school takes less than an hour for everyone. Life is good at those times. And they know that the sooner they get done with their group of units the faster they get to those easy weeks. So sometimes they'll even work on Saturday.
They also know that if they work really hard they have more time to play each day.
Now for AWANA, my kids have always done really well at being diligent and learning verses. However Jayden finished the books and for some reason the others also decided that they really were wanting to not learn verses last semester. So this semester I decided that whoever learned the most verses (basically got the most pages signed) gets a prize at the end. I haven't decided the prize yet... It'll probably be something simple like a day out with Mommy or they get to pick out an outfit for summer or shoes or something. It's really gotten two of them back into it. The third has never really cared overly much for things like that and has lost her book anyway.

So we will see what happens. I might even make a chart where they have to get so many signed and we'll do a big family thing.