I give my kids £400 a year, excluding occasion wear like suits and prom dresses and the like.
I split it 150 summer, 250 winter, given now in spring and again in September/October.
Initially I set a budget and then went and sat in Costa while they browsed and tried on. I also specified what their allowance had to cover - 2 pairs jeans, 4 tops, a hoodie, boots etc. Then I would go and pay for the items.
If they didnt spend all their summer allowance, it would roll over to the winter allowance - Dd managed to save enough for a Holister coat.
Ive always said if they want big brand items, then they have to compromise elsewhere - so they can have big brand jeans if they get Primark tops. Or they can buy a handful of clothes from the fashion shop, rather than loads from a cheap shop.
They get no other items from me. HOWEVER - DS, 16, is still growing and at 6'3" now, tends to outgrow everything at a staggering pace. So I am, at the moment, more lenient with him, especially with essentials like jeans and shoes. Im hoping that the 34" leg jeans will actually last him, and he is not going to get much bigger (sobs quietly into hands).
I also did the same with DD1, now in her 20s, when the boob fairy arrived and we had a new cup size every 4 months.
So this last 12 months, I transferred the money to DDs account and set no parameters. She spent most of her summer money on bikinis. and shoes. And accessories. I ignored the heavy hints that she had nothing to wear thereafter.
In winter, its been cropped hoodies and high heels. Then she moans that she has no jeans that fit her. I ignore it all and say "Thats why you have a clothing allowance."
One gets pocket money in addition, (she is 15); the other works.
I will do a big shop with them on my budget this september as they both head off for 6th form and will need a bigger selection of jeans and hoodies..!