A great way to make sure your buffing and polishing is good enough, is to check it without any polish on the paint.
The goal is to be able to wipe the paint down with water borne cleaner, and not be able to see a difference. If you have more polishing to do, the water borne cleaner will expose the remaining scratches or swirl marks.
Isopropyl alcohol works better than water borne cleaner, but it is much more aggressive. So, use it with caution!