You can use a Satin sheen. It is not as shiny as semi-gloss. I use it on trim quite often. It would also be a good paint for a hallway because it's usually easier to clean than flat paint (for the wall).

A few years ago, hubby and I painted the entire inside of our home. Just as a reminder, make sure you do all the necessary paint prep work so your paint job adheres nicely: wash and rinse all walls, ceilings, doors and trim. We used Behr Ultra Paint & Primer Scuff Defense: matte for walls, and satin for doors and trim. This paint is excellent quality, goes on easily, no issues. Use high quality brushes and rollers for the best outcome. We painted all our rooms and hallways off white. Best of luck on your journey!

In my house I have the baseboards painted the same color as the walls, in the same sheen. I don't care for the look of highlighted trim in most cases, unless it's wood.