Well that kind of depends. If the next move is on a painting then sometimes it's better to just leave it and let it sit for a while.
I've often fallen into the trap of over thinking and over working a piece, which has resulted in a muddy mess.
In true Blue Peter style - here's one I made earlier.
Break out the sander.
But if you've finished a series of work and don't yet have a plan for the next series, then this is what I do now.
I'll dig out inks, paint, crayons and make some of my own collage papers. It's a good way of using up spare paint on your pallet too. There're lots of ways of creating these, my current favourite is painting random marks on wet strength tissue paper. One of the advantages of using wet strength tissue, (easy to find on amazon) is once the paper is glued onto the work you're doing, the tissue becomes transparent, just leaving the marks - genius.
This is a useful exercise, not only is what you produce something that will add, layers, depth and texture to your work. But equally importantly when all you're producing is a muddy mess, and we all get that from time to time, then this is a way of not becoming disheartened, but showing up in the studio and playing with paint and materials. You never know where it might lead and you've still got something useful to show for the time.
A big bag of bits and pieces...