KahnRa

I use Centripetal (Centrifugal??) force to deorbit my orbiting stages. Just start spinning end over end with your head / tail pointing at the planetary body, once you get up to maximum rotations and as the stage you want to separate gets closest to the body, separate it. The force will fling it down, and away it goes. I remember reading once that this is what they do to get rid of rubbish on the space station (it may have even been in a fiction book).