flow, flow, and more fow for a frag growout(sps, less flow for others). strong lighting and clean water.
this is going to be hard to do with a ten gallon. just growout your frags in the cube. maybe make a small rack off to the side of the tank (eggcrate glued to an old magnet cleaner). or better yet find a way to put a sump on your cube(maybe inside a cabinet next to your tank), light it up, and grow there. this will increase the volume of water on your cube also. you could even put the growout on an opposite light cycle with macroalgae to help keep oxygen levels up/co2 levels down.