Target.

My eye never leaves the spot I want to hit......I just let the pin float over that spot and concentrate on the release process.
I'm more concious of how my peep aligns with my sight ring than I am with the actual pins themselves. Once I am confident my peep is aligned precisely the rest is just looking at the target and execution.

It gets even easier to do when gapping pins. When you have a pin sight set up for say the standard 20-30-40 yardage settings, when you want to shoot 25 yards you don't aim high with one pin or low with the other. I aim with the imaginary pin in between the 20 and 30.....just stare at the spot you want to hit by bracketing it. It's essentially aiming with air as you don't look at either pin at all, just the spot you want to hit.

If you shoot closer to or farther from one pin or the other's exact yardage you just shade the gap a little in the necessary direction.

You'll be amazed at how accurately you can shoot by simply staring at that spot you want to hit.