Ha I have just been scraping paint drips in the bathroom I am redoing.

While I love the contrast of bright white trim and a midtone color, I did a lower contrast with a pale wall color and the oops are a lot easier to touch up. White on white in a small bath could visually open the space, but you could vary the finish for a texture contrast. Use your semigloss on the walls and a hi gloss on the trim woodwork. Eggshell or satin finish would be even better on the walls. To keep from being snow blind use colorful towels, rugs and other decor.

Another option would be use your white semigloss on all the trim first. Then depending on how much is left, mix the left over with a flat paint in a color for the walls. That could be just adding a sample jar or two if you have most of that gallon after painting trim.

A couple trick for neater painting, good masking tape and a damp sponge to quickly wipe drips as you go. Then a cheap artist brush to touch up details.

What great ideas you have. Thanks for inspiring me.