Hopefully this will help others, finishing has been one of the things that I have struggled through the years and I have a few tips that would hopefully help others.
-Shining a flashlight on your project with all the lights off in your workshop will show you every flaw in your piece prior to finish. wiping your project with mineral spirits, especially with walnut and cherry will show you any glue that was missed.
-Vacuum and wipe your piece prior to finish, spraying compressed air could get some oil etc. and cause "fisheye" in your finish.
Polyurethane, I don't use your standard oil Poly because of the drying time, I use the oil modified which dries faster, I like the water based, but grain raising was an issue too.
Lacquer is my favorite finish, dries fast and lays extremely flat. I sand after the second coat of clear on my projects with 320 grit, 3rd coat the final, except on tops where I may use 4/5, sand with 1000 grit, wax etc.
In staining, I prefer oil based stains for Oak, but Cherry, Maple and Pine, I choose to spray my finish, making my own stain with concentrated stain and denatured alcohol, the stain almost immediately atomizes and you limit blotching.
Painting cabinetry, I gave up on an HVLP system for that, for me I could never get the consistency right and was always left with a mess. I went with a cheap Graco Project Painter and the results were fantastic. Overspray will happen, you will lose a lot of paint, but the tradeoff is a factory finish, using a fine 313 tip.
HVLP, I use an Earlex Spray Station, 1.5 mm tip for spraying stains and a 2.0 tip for finish.
I'm definitely no expert on finishes, but there is nothing worse than completing a project and the finish doesn't work out. I've sanded out many pieces of furniture etc. than I would ever love to admit.