So, one of the things generally established in the EU is that a Jedi can use the Force to provide a boost or slow themselves, but they can't use it to hold themselves up. On the other hand, Jedi can use the Force to hold up and move other people or objects. There also doesn't seem to be any other rules regarding conditions for using the ability; ie: no leverage required.
So... Can two Force Users fly by using Force Move to hold each other up? Debate!