My kids are 10 and 6.5. The 10 year old is easier than the 6.5 year old. He understands the importance of helping out to be able to have what he wants. We also don't reward for helping out/chores. We also don't call them chores.
(School is "work" for my kids, their "job," and they get rewarded for that - this works for us, and the grades/feedback from his teachers improved tremendously. Rewards are not on final grades, but random tests/feedback, when I feel they worked hard per se.)
Currently, (10 y.o.) he has to keep his room clean, clean up after himself when eating or playing, empty the dishwasher/put away dishes, put away his clean laundry and recently, take out the trash. Those are the routine daily/weekly tasks. Other things pop up, but are more random - vacuum, dust, wipe tables down, etc. I usually give him something to do and tell him when it needs to be done, so he can manage his own time. Sometimes reminders are needed, a lot, and others not so much.
He is starting to load/soap/turn on washer-laundry, and we are incorporating a night he has to pick out what we are eating and help make it.
I don't ask for much because cleaning is more of an ongoing/daily thing, and add a little/new step at a time. Slowly.
As for the smaller one... he's my groaner. lol! It's a fight with him. ugh. He has to help empty the dishwasher, put away said dishes, put away his clean clothes - drawer ones, clean up after himself after eating/playing (this is a STRUGGLE!), and recently, dusting (with a wand - he loves it, lol!).
As he get's bigger, we will incorporate more things for him to work into a routine.
Before both can have play/video/screen time, they have to make sure they finish homework, clean what needs to be done, and check the dishwasher/trash/laundry. Then they are on their own time.