Determine your dominant eye.
I'm cross-dominant, meaning my dominant hand and eye are on opposite sides of the body. I'm right handed but left eye dominant. I do pretty much everything right handed except shooting my airsoft gun; in order to aim down the sights with my left eye, I need to shoot left handed. I can shoot while aiming with my right eye open and left eye closed, but it's somewhat uncomfortable.
Any other cross dominant people here?