How do you compose accurately with an Instax Mini 90?

My composition always seems to be a little off. Anyone have any tips?

The viewfinder is offset from the lens, so what you see will be slightly different from what the lens sees and the discrepancy will be greater at closer distances. This is called parallax. From maybe 10 feet to infinity, the difference is small to nothing.

Also, I suspect that the viewfinder will show a little bit less than what appears on film.