When we started doing allowances we were torn on all sides of the issue too. We had friends that did it every which way and I was reading you should do it this way because... things all over the place with so many different ways. DH and I started a compromise system.
They receive a certain flat fee.
Certain chores are required because they are just part of being in a household. I do not get paid to clean, my kids need to learn that they won't either. They have to keep their rooms and belongings up to par without compensation. They are in trouble if they do not do these chores, period. I don't take away their allowance, but other special privileges like staying up late on the weekend.
They can then earn extra money for their allowance by doing optional chores. These chores pay various amounts and some can be done daily, others only periodically. They include things like washing the dog, feeding the dog, routine cleaning of the bathroom, washing the baseboards, etc. Basically things that you opt to take on (you can opt to not have a pet and therefore petcare isn't required) or chores that aren't routine. We keep a chart to keep it organized.
Also, we do make them follow a teaching method with money so that they learn how to handle money. 10% goes to charity, 20% to savings (a parental account that they get when they turn 18) and the rest is their to do with what they want--save or spend willy nilly. We also don't foot the bill for things they do with their friends, unless it is our idea. It is really teaching them to budget and decide wisely.
I have found that it works really well for us.