We tried an allowance system with DD1 when she was five. We said she needed to make her bed -- which included setting the million stuffed animals ON TOP of the blanket in some sort of neat pile -- every morning, and she needed to help me straighten the play room every Friday before dinner. If she did these things, we'd give her $2 at the end of the week.
This lasted MAYBE 2 weeks, and there was a lot of harassment. We gave up. During one argument, DD1 said, "but I want my allowance!" and I said, "Well, you just need to do your chores next week and then you'll get it, absolutely!" Her response was "Well then I guess I'll never get any allowance." She basically admitted that she was not going to do the chores. We did not make a big deal about it. She just wasn't ready for regular chores...but that meant she wasn't ready for allowance either, and both were ok with us.
From time to time over the course of the year, she would ask for some item in a store, and I would say "you don't have any money for that, sweetie. Maybe you could start doing your chores again, and then you'd get some money every week." She would think about it, and then shrug and say "maybe."
It was not until a recent visit from my parents, nearly a year after our first introduction to the idea of chores, when DD1 decided she wanted to try again. I actually didn't realize she was doing it -- but then noticed that her bed was made when I went up there during the day. She started even asking to sleep on top of her covers with a throw-blanket, so she would be able to have a neat bed in the morning. After she'd done this for about 4 days, I told her how nice her room looked, and how proud I was of her for doing it without even being asked. I reminded her that if she kept it up for another 3 days, and then we cleaned the playroom together, she'd get money. And I also mentioned that since she was older, it would be a little more money.
The kid got allowance this weekend!!!
I guess the point I'm making is that sometimes they are ready for regular chores, and sometimes they're not. Natural consequences work pretty well for big messes (like painful feet from stepping on polly pockets all over the floor). Other than that, I think it's a waiting game. YMMV, of course.