1) Pot your sample with enough epoxy that you can comfortably hold the sample.
1) Start with a fresh piece of sandpaper every time. You don’t know how the last person [mis]used it.
2) Don’t skip over intermediate grits. The intermediate grit paper is there for a reason – and it doesn’t save any time or effort to go from 80 grit to 600 grit.
3) Wash the sample after every step, so you don’t transfer larger grits to finer paper
4) Make a sample your proud of. I like to polish both sides and the perimeter of the samples I am working with, if I have time. This is impressive when sent back to a customer, or it can be used as a display at a trade-show.