I bought a cheap set of side trims that were quite dented so i could practice repairing them before attempting to repair some dints on a couple of the trims on my car.
There are several videos on YouTube on how to do the repair, the technique and method to get a good result – which helped me get a good result with my own attempts.
I found the whole process quite relaxing otherwise i would wonder whether the time spent justified the alternative of buying new trim pieces!!