Looking at your original question as two parts:
ORIGINAL: Go Pens
Is there anyway to predict which way a wing tip stall would occur (left of right) before flying a ARF for the first time?
And
ORIGINAL: Go Pens
Building the G.P Escapade now and I thought it would be helpfull if one knew which wing would drop first in order to balance and prepare for that event.
As I said earlier, get lots of altitude and make it stall. More than likely, both wings will stall at the same time and the plane will just nose over slightly and recover.
"Tip Stalls" will usually occur when you are flying too slowly through a turn. As you turn, the outside wing is moving faster than the inside wing and vice versa. So since the inside wing is moving slower, it will stall first and the plane will fall to that side - usually resulting in a major loss.
If you are coming straight in on final, the chance of a tip stall is relatively small - In fact, in 50 years of flying I've never had it happen. If a plane tip stalls on landing, there's not a thing you can do about it. For that matter, if the plane stalls at all on landing there's nothing you can do about it - You're too close to the ground to recover from it.
ORIGINAL: Go Pens
it would be helpfull if one knew which wing would drop first in order to balance and prepare for that event.
When a wing stalls, you have no control until the wing starts flying again - which isn't going to happen if you're less than tree top high - so there's nothing you can do once it happens. The trick is not to let it happen. Keep your flying speed up until you are ready to set the wheels down.