Our daughter is almost 18 now but we never had a set allowance.
We are lenient with paying for things as long as she maintains her excellent grades in AP and honors classes and Varsity cheerleader as well as community service. Now if she were to become a slacker, the $ would dwindle. He$$ would freeze over if this kid ever became a slacker... she is very driven just like us.
That said, she buys all of her clothes, pays for most of her entertainment expenses.. We cover all car costs, food, and anything related to education.
My hubby frequently hides a $20 or so in her glove compartment of her car. It is now a surprise to her to see what he has left for her in her car.
She is on payroll for our company and I cut her a check monthy but it goes straight to her savings account. She shadows me learning how to run a business, manage financials, payroll, taxes, etc. She is also a very popular babysitter in the neighborhood and makes about $15 an hour CASH babysitting on weekends. Her babysitting style is not to sit on the couch... it is involvement as in teaching Spanish, tutoring if needed and the children's favorites are her arts and crafts she brings for them to do.
It is pricey for kids to go to movies a lot, etc around here. You can blow $50 on an ok dinner. My house is usually full of 4-6 teens on any given weekend night, including ballgame nights where I keep food stashed for them to cook, I keep my homemade marinara on hand by request and all they have to do is make pasta, then they watch movies, play pool, etc. My food bill is higher but that is perfectly ok with me because at least I know where they are and they are safe!
Good luck