Stand at least 7 ft away from the wall, in a well-lit room.
Opt for a wall with feature points (avoid white walls).
If your wall lacks feature points, stick 2 or 3 Post-its.
Move the picture as needed.
Stand at least 7 ft away from the wall, in a well-lit room.
Scan the floor (avoid reflective or glossy surfaces).
Drag the line at the base of the frame to where the wall meets the floor.
Move the picture as needed.