First of all: Hardcore stained wood fanatics – Be cool, don’t jump my ass. kthnxbye.
I have been painting the wood trim in my house. Someone put this poopy colored (no exaggeration, I’ve had a baby, I know) opaque varnish all over the wood. You can hardly see any wood grain anymore, but is very glossy and the dark color drags down the whole house.
Then paintable caulk in any seams.
Don’t forget to caulk along the sides of the moulding where it meets the wall!
I use my trusty oil based primer. I know that there are latex primers that say the stick to glossy surfaces, but besides the BIN kind, I just don’t trust them. I have been using Zinsser, although I am not loyal to the brand. Make sure that you have mineral spirits on hand, very helpful for any drops and cleaning the brush. I like swishing the brush in mineral spirits, dawn soap, and then swishing in new mineral spirits for brush cleaning. For mini foam rollers, I would dispose of them after each use.
I use my brush to get the primer into all the little nooks and crannies, and then go over it and the flat areas with a roller. The first coat will NOT look good. Or opaque. Or white. In fact, it’s going to look pretty awful. That’s cool.
I am a double primer sort of girl. I feel like the second coat gets any tiny missed spots. I use the same method of the brush and mini foam roller.
If painting white, after the oil based primer, do a second coat with white latex primer. I use Zinsser Bulls Eye 123 primer. I thought that I had a picture of this coat, but I guess I don’t! Sorry! It will look brighter white, but still patchy.
If going from dark wood, like my trim, to white, expect to do at least 4 coats (more likely 5.) Two of primer and 3 of top coat color. I personally like Floor and Porch paint for trim, it’s satin and durable. I used Sherwin Williams in Snowbound 7004. This is the 5th coat: