First step, get a friend. Got any? Sweet.
Get on your bike with cleats installed.
Lean against a wall or use a trainer and have your friend put the crank at "3:00." So as your friend is looking at your foot, the crank is at 3:00.
Lift the heel slightly.
There's a bone that sticks out to the side behind your big toe.
You want that bone to be over the pedal spindle.
Good place to start anyways.

Shoe dyslexia plays a part in this too. Make sure you're moving the cleat the right way. Once you turn over a shoe to adjust your cleat, your brain might malfunction and you move the cleat the wrong way. Happens to the best.