There is a little bit of sanding skill and a little bit of fudge factor involved. Take your time, it either will be nice, or a pile of crap.
If you think you got it nice, take some Naphtha on a rag and wipe down your work.
This gives you a preview of what the clear coat will look like.
Sometimes it looks great dry, but looks terrible when Naphtha-ed.
Other times it looks dicey and grey, but comes out perfect when wet.
If the damage is too bad to sand out, don't despair.
Patch any soft wood fibers with wood filler, sand smooth, mask with tape and simply paint in the "layers" of plywood.
I know this sounds flaky, but I've done it 100s of times and 95% of the time the customer never notices - but if I did not paint it, they'd notice for sure.