By doing a "test spot." That's where you take a small section (usually on the hood or other large, flat area of the car) and try to correct the defects using a product that is one step (or so) less aggressive than what you think will correct the damage. After buffing that spot, wipe it clean of product and inspect the results, if the damage is still there, go a step more aggressive in another spot.
In other words, start with the swirl remover on a polishing pad, then swirl remover on a cutting pad, then compound on a polishing pad and finally compound on a cutting pad, stop getting more aggressive once you are able to correct the finish with the combination you are currently using.
Make sense?