It kinda helps that we have a paint store in Dunellen that's been family owned for about 100 years: Yospin's so she's been taught by people who know what they are talking about.
1. Get good paint. She is a diehard Benjamin Moore fan. I have not listened to my mom, and so have bought paint from bigbox places. The paint lost its luster fast and needed a lot of coats to look smooth. Listen to your mother.
2. Use those small rollers, especially for doors. When she was explaining why... "I like a short nap." I answered "I do too but the boss frowns upon it."
3. Paint the molding and doors a semi-gloss decorator's white. It's made at the factory so you know it will all match up throughout the house. The semigloss makes it easier to wipe clean.
4. Use an angled shorthandled brush for cutting in. You'll have more control. And won't have to use blue tape.
5. Don't bother taping the windows. Just cut in as much as possible and use a straight razor to clean off the window.