There is a bit of a science to it, things to consider:
1) feet in to center of the scope is stronger, since it moves the rings farther apart. This also leaves the least about of room to move the scope front or rear ward for optimum scope placement
2) on some actions, feet in or out can cause the ring to hang over the open part of the action. Some are solid all the way across, so no issue
3) See #1, in some cases if you are mounting very low, you need to move the objective forward so bell is farther along the taper of the barrel to have more clearance
4) it does not matter if both feet are in or out, you can do front in, rear out. They do not have to match
4) in some cases, how you orient the rear ring/base can cause the bolt to hit the ring
5) always figure out how you want to set it with your scope at maximum magnification. Many scopes do not have constant eye relief, you set everything up at 3x and then check at 9x and your stretching to see through the scope. Unlike piccatinny rings, you can't just loosen a screw and shift a ring. The whole works has to come off.
6) these are great and super light, but not the strongest. I always use blue Loctite on the screws to the action, since you can never check or tighten these without removing the scope. the ring screws can be checked/tightened anytime, plus there are 4 of those.
