If you always carry your change with you and spend it whenever possible, your coin quantity will remain pocketable.

You gotta be committed enough to hand over a twenty dollar bill alongside a quarter, when paying a $19.17 bill for example. Rather than take in 83 cents you take in 8 (and score a dollar.)

I don't know about him, but my Safeway has a change machine up front. You can either get the total in cash, minus commission, or store credit for the whole amount.

My bank in germany has a machine, where I can put them in to be transfered to my account. (but I think I only ever did that once)

In euroland bills start at 5 euro, below it is all coins. So when paying cash you get a lot of 1 or 2 euro coins as change.

I change those coins into 5 euro bills whenever possible, stores always want change. Small coins go into a big jar that we use to tip people like the pizza delivery guy.

If the jar gets too full I simply donate the jar as is to a charity I know.

Not much, because I also pay in coins in exact amounts.