The finer the pad, the finer the product the less swirls are introduced.
Swirls are micro marring and they are going to be introduced into the paint at some point during the buffing stage. The question then should be, "What can be done to lessen them?"
1) Know your product and pads - There is a term I use called "opening the paint". This is where I use a heavy to medium cutter/leveler and usually a LC orange power pad or if needed a wool pad. I know with these products/pad combos I am leaving behind marring. You can't just go to a hand wax after this step and then expect the car to be swirl freee and look good.
Logically after one "opens the paint" one then needs to "close the paint". So after our initial leveling stage I would move to a polishing pad and a mid-level polishing product. By mid-level I mean something that is designed to remove1500 grit sanding marks. My personal 2 favorites are Hi-Temps Medium Cut and a bit lighter is Menzernas Intensive Polish.
Next comes something even finer applied with a finishing pad. I prefer Hi-Temps Light Cut, Akrya's 2000 Leveler or Menzerna's Final Polish. This step may be followed by Menzerna's Final Polish and a LC blue Xtra fine finishing pad.
The swirls and fine scratches should no longer be a problem BUT if it is a dark color and you wish to see if you can get some extra depth and gloss I would recommend the Cyclo and AIO. AIO can also be applied by hand and then topped with the sealer of your choice, as long as it has no cleaners in it.
Dirty or worn pads will harbor grit and rough edges which in turn may cause swirls so change pads often. Keep them clean and don't allow your product to cake up in the foam pads.
I rinse my pads often during a buffing session, this is a good habit to get into.
2) Know your speed limits - This means that you should know just what your skill level is when using a high speed. I rarelt go over 1800 rpm's, especially on todays lighter sheet metal and thin clears. You also need to get familiar with your product in the sense of what does the product maker recommend as far as pads and rpm's? If it recommends a small drop for a 2x2 area then don't have the mindset that 4 drops will work better because this will most likely lead to caked up pads.
As already noted the magic of the rotary lies in its ability to transfer heat and friction to the paint surface and when combined with the correct pad and product will level the irregular paint surface. This is our goal BUT to do so without burning the paint. Again as already noted we want "warmth" but not so hot that you can't keep your hand on the surface.
For removing scratches you may need to use between 1500 and 1800 rpm's. To remove finer scratches/swirls you may find 1200 to 1400 rpm's works best. For final polishing you may find 1100 rpm's is just fine. Contrary to popular belief, a lower speed is not always the easiest to control and many times more swirls can be introduced from the lower rpm's. I personally find the 1200 rpm range about the best of both worlds. I can control the buffer and apply plenty of heat and friction.
A mechanical cleaner/polish (one with abrasives) may works best at a lower rpm so that the products abrasives can properly break down and do their job.
A chemical cleaner (cleans by solvents/some abrasives) may respond better to a higher rpm because of the extra heat and friction.
Lastly, don't work so hard at working the polisher. In other words let the tool do the work, allow it to work. I often see 2 critical mistakes when a person learns the rotary, which I also did as I learned, and those are 1) using a death grip on the handle, thus they "steer" the polisher with the handle and 2) they "push" the polisher across the paint.
The first mistake can be corrected with practice and always reminding your self to ease up on the grip. A tight grip on the handle will cause you to lean on one side or the other, causing you to open up the buffing pad face which leads to swirls. Many times I place my left hand on the housing where the spindle is located. On the finer polishing steps when using a lower rpm a second hand is rarely needed. Again let the tool do the work.
The second mistake can be corrected by again allowing the tool to do the work. If you have it set at 1100 rpm's don't "push" the polisher across the paint because you fear burning the paint. This leads to major swirls (and major disappointments) as your are not allowing the tool to properly break down your product. Again you should get the paint to the "warm not hot" level.
There is much more but hopefully this little bit can be of help to some.
Practice, practice.....
Anthony