We have given DD pocket money since she was old enough to have some concept of money & what it was for. In her case this was age 2.5. & her first pocket money was £1, which allowed her to treat herself in the £1 store or save for bigger things which she soon got the hang of.
Each birthday her pocket money increased, initially by 25p a birthday, rising over the years to 50p & a £1, by 12 this was paid monthly into a bank account
We have never given her money for chores or good behaviour, I personally don't believe it teaches a good message that way, these are life skills & jobs that are part of family life, not a way to earn. Though we would take money off her if she refused chores, or badly misbehaved. We did also for a time when very young use tokens made from painted pennies as behaviour points, which when she had saved enough could be swapped for an extra treat, but never money.
I felt this was a good way to teach her how to save for bigger things, how to budget & that chores are just something you need to do in life if you want to be comfortable not upset people you share a home with. I had similar as a DC & have always been good with money & take responsibility for my own space. DH is the same & this was normal for him too, so we figured it made sense.
She does now at 14 get a lot more than the national average though, this is partly because she is now responsible for topping up her own phone & buying most of her own clothes. She has also been seriously ill/disabled, so gets a portion of her DLA as she was suffering the most, this seemed fairest & shopping has helped keep her sane during a very difficult time in her life.
She is getting better though & knows this extra money will end soon, so she is now looking at ways to earn money to replace it & looks set to do well with that too.
We do give her extra money as a treat for any big effort in school reports, exams etc, though this is always for working hard, not for acheivement, though in her case, that always means she has achieved well too. I have also given her extra to treat herself if she has ever gone over & above to help others, school reports mentioning how kind & helpful she has been to others, giving up her time to raise money for charity etc.
I felt this all enforced positive behaviour & so far, seems to have good results