I'd suggest you to not really think about it right now, but just methodically work on every combination.
Once you get used to the pattern, your hands will tell you themselves what works best for them.
I think that's very good advice. I've always felt that part of solving a problem is finding a solution from within the problem itself, rather than applying the answer from the outside, whether that answer is right or not. Practicing to me is in the thrill of the hunt!
Students complain, but if I tried everything in the first two bars, it would take forever to learn the piece. But would you want to learn the rest of the piece without being able to play the first two bars? Think about it! Also, when one is truly concentrating, perception of time changes, and with good concentration, a little bit of work always goes a long way. Never worry about how long something will take; worry only about achieving quality!
Walter Ramsey