Noticed recently: ceiling medallions used as decor. Vintage medallions make a big design impact with little environmental impact.
Above two photos: A restaurant installation by Toronto-based Commute.
Above L: A Scandinavian living room with a vintage plaster ceiling medallion. Above R: A vintage medallion as part of a tabletop display. Both via Vita Tankar Cecilia.
Above: Classic Ceilings offers a wide range of wall and ceiling ornaments, including a good selection of paintable high-density furniture grade polyurethane medallions; prices start at $22.20 for a 10-inch Arstyle Medallion.
On the subject of ceilings, here are some ideas from Remodelista for overhead light fixtures: 10 Easy Pieces: Ceiling Socket Fixtures.