Top 10? It's not really that sophisticated - it's just the temperature and rpm requirements.
You have to vapourise it, and then repeatedly separate it via a vortex - a centrifuge. Have two outlets, placed at different points and the uranium will separate into two - enriched, and depleted.
Repeat many times and you'll get the nuclear level. Same goes for most isotopes, it's the same principle as distillation - one of them is heavier than the other - except it's done with two almost identical types of heavy metal.