Mark a line on the top of the backing plate with a perma marker and you can then use this to judge how fast the pad's rotating.

When you're using it, with the correct pressure against the panel, it should be spinning at least 1 full revolution per second (faster is fine). Slower than this and you're applying too much pressure.

Try to move the machine slowly - about an inch per second is good.

Start with the least abrasive polish and pad combo you have available as often less abrasive pairings are enough and you won't have removed unnecessary paint thickness.

You only need a few peas sized blobs of polish on the pad per section.

Work on small areas at a time (12inch x 12inch, or fractionally larger is ideal). That way you're working the diminishing abrasives down at roughly the same rate over the whole work area which is key to getting a marr free finish.

If I think of any more I'll post up