M.J.
If they are getting a big wad of cash I tell them they have to put a certain amount in the bank. I don't do a percentage, I just say $20 or whatever.
Now when they get lots of giftcards, I find that hard to control. Luckily they are into video games which are pricey, so they can use them on that and that's fine with me.
I think it's important to let them spend their money on stupid stuff so they realize that when it's gone it's gone. My kids have chores and they get an allowance, but I don't put a price on the chores. They have to do them because they are part of the family. Their allowance is theirs to do as they please and they have gotten pretty good about saving it up. They also use it to buy candy and pop if they want it (with my approval). I even started telling them they had to use it for other stuff like clean jean day. They go to a private school and sometimes for fundraisers they have pay $1 to wear jeans. One of my kids is like "it's not worth it!" and won't fork up the cash!
I tried getting the piggy banks with the save, spend and donate sections and it was terrible. They are hard to put bills in and hard to get money out and then I was nagging about what money was going where.
I have also been teaching my kids about coupons and I tell them "it's free money!" So now they are asking me if I have a coupon for something before they walk over to the CVS to get it. I also won't buy certain things unless they are on sale or I have a coupon and my kids now look at the grocery sale ads!
M.