Prior to age 3 kiddo just got all of our spare change. It was HILARIOUS because he decided the "best / safe" place to keep it would be his underwear drawer. ((Apparently it's an instinct)). And he'd hunt for it as well as ask me for what was in my pockets at the end of the day (metal change only, not paper).
Starting at 2ish, however, he also started campaigning for a puppy. So around age 3 I started giving him an allowance and made the still standing deal that dad and I would match his savings for "big" purchases. It wasn't linked to anything, but was "pocket money" for him to save or spend as he saw fit. ((It's quite fun to see what a 3yo sees fit to buy)). From 3-5 he got $5 a week. Once a month he'd go half with me on buying a train or book from the store. He'd buy treats from the store, broccoli from the market (his favorite food for years), donate some... and in a little over 2 years had saved $400. Half the adoption fee for our puppy and half the projected costs for food and vet bills for 6 months ($800). Then he started K and got a new "campaign". He wanted a MacBook. He only had to save $500, and his allowance had increased to $7-$10 (his allowance increases every year on his half birthday) but it took him 3 years to save for it (he got it a few months ago). 2 big setbacks were Summer Food Programs for kids (he gets highly offended/horrified at kids not being able to eat breakfast or lunch when school isn't in session...it's not a charity I donate to, but he feels close to it, so I encourage him to follow his heart but NOT to give more than 1/3 of his money away), to which he gave over $70 each summer, and an illicit xBox purchase (he was signed into dad's account and bought over $100 worth of games with just a few mouse clicks). He had to pay us back for that one.
From K until present his allowance IS linked. He has a list of things that need to be accomplished every day. Chores, school, hygiene, helping out with family projects, and play. I believe that balance is very important, and as an adhd household, balance can get rather elusive... so rather than just have chores on the list; every day also his play gets checked off, and bathtime, and helping others with ______. Whether that's cooking dinner or decorating the xmas tree. He gets a flat rate for getting everything checked off and a "bonus" for doing them all in a timely fashion with good attitude.
Every year as his allowance increases, so does what he's responsible for paying for. Last year we started going dutch on "extras". Like a movie, or going out for lunch. If he proposed an outing and I agreed, we'd go dutch. If I proposed it was my treat. (Sometimes he'd treat me, with his chest all puffed out). He gets his first bill this year (and he's sooooo proud of it, and making sure it's paid every month)... he's responsible for his $10 a month cellphone bill. He's also now responsible for buying birthday gifts, and for saving $5 a month for his next year's season's pass.
Here's the quick rundown... 'cause I've probably been rambling:
8.5 = $15 per week (1.50 a day + 4.50 bonus). Responsible for Cell phone bill ($10), xBox Live Membership ($3), & 1/2 his season pass for snow ($5). Also gets his first bank account in his name / with card & online banking so he can start to deposit his allowance and be taught how to use a debit card (tracking purchases, balancing/not overdrawing, etc.).
Age 8 bought his MacBook
7.5 = $10 per week ($1.00 per day + $3 bonus) Responsible for 1/2 of "extras" (like lunch or movie), & xBox membership.
6.5 = $7 per week ($1 per day... no bonus at that point) pure pocket money
Age 5 paid $400 for puppy and care/upkeep
3 - 5.5 = $5 per week (no bonus) pure pocket money
2ish = whatever spare change I had in my pockets or kiddo found laying around. House rule: metal money only. If he found a $20 on the counter and a bunch of change, he could take the change but had to leave the paper money.
ALL of this has been a very organic process. The only thing I knew going into it is that by 14.5 I want him paying for *everything* (sports, clothes, school supplies, entertainment, etc., plus his "share" of bills or the total of his "own" bills) that I would be paying for otherwise. Point being that I don't want him unleashed on the world without real practical money experience as to how much things cost and how to manage his money. I want those lessons as solid as stone before he moves out on his own. And if I'd be paying for those things otw... why NOT let him learn by trial and error while still in the safety net of being home? How we get there though, there's no strict "plan" other than to gradually increase both the money he has to work with and his responsibilities. "Increasing levels of responsibility" is a theme in my house. Of course, with more responsibility, also comes more fun :)
Sorry if this has dragged on a bit.. I probably should have gone to bed a bit ago, & I tend to ramble when I'm sleepy. If I remember I'll try and make this a bit more concise tomorrow.