Right now, what I do is reinvest my whole payout every week.
I´m reinvesting some of it too, trying to keep ahead of the difficulty increases.
This is a good attack, At the moment, As I have low GHs and trying to build them up, I put in a little more each week than I get, This will bring me up faster to the point where I can put in what I get back, and not have to spend anything.