I basically just leave it at 100%. I'm a small account and the price of Steem is low, so a lot of the time that is the only way I can actually give people even one cent. I'm glad to do it though - and I try to keep from totally recharging. I'm too small to get much curation, but I'm glad to at least make a difference for other people.
I'd be curious to see a pie (especially if I can use it in an article). My current SP is 14.7 + 71Delegation
If it's at 100% (probably the right thing to do with your current SP), then the pie will look quite plain..
If you really want a pie let me know :)