What sheen do I use?
Using the right sheen on your surface can make or break your paint job, even if the color is perfect. When I am asked (frequently) about sheen, I first determine if there are little kids or large animals that live in the house. If the answer is "yes", that means the walls may need a bit more washability. I usually recommend an eggshell finish. If it's "no", then I prefer a matte finish. Not to be confused with a flat finish, matte is still washable. Flat is not. For rooms that will not get extra wear, such as a master bedroom, matte is almost always my first choice.
For doors and trim, I choose a satin or semi-gloss finish. Sometimes I find semi-gloss too shiny but it's a great option when extra durability is needed.
If you are painting a high-traffic business or public space, consider using semi-gloss for doors and trim and an eggshell finish for the walls in a super-durable paint. Ask your paint retailer for recommendations.