What kind of plants are best for topiaries in a low/moderate light area?

My fireplace is on the south wall of our house, flanked by two windows. Though these are south windows, they are partially shaded by the house next door, especially in the winter, and the light coming through them is angled so that it never reaches the fireplace mantel. The only other window in the room is on the east wall. So topiaries on the mantel would get indirect bright light.

I have lots of outdoor and houseplant gardening experience, but have never done topiaries before - so easy-for-beginners suggestions would be great. Thanks!