After stripping our wallpaper with a clothes steamer, the walls were mostly bare, but there was some glue residue and tiny paper scraps lingering. (In this photo, I have not painted yet, that is just what the walls underneath the paper looked like!)
To prepare the previously wallpapered walls for painting, the method I used was not all that different from what I used anytime I prep to paint a room (dust and scrub with soapy water).
This time, I bought a big sponge with a scrubby side and used a 1:1 water and white vinegar solution. This helped loosen any remaining glue and paper left behind. With a little spackling and sanding here and there to spruce things up, we were ready to paint.
Our walls are weird and even when we have done a white paint going over another white it still takes three coats. I did not prime, but maybe will experiment with it in the future.
I also often buy the cheapest paint, so testing out higher quality ones might lead to less coats required. In here, I need two coats each of cutting in and with the roller.
The walls are Valspar Four Winds (love) and I am waiting to do the trim because I have bigger fish to fry.
Even though the dated wallpaper was neutral-ish, now that it is gone the continuous white makes the entire first floor feel larger and more open. And just like, CLEAN.