Art is a great way to stamp your personality onto a space.
Lately I am seeing large canvas wrapped prints, either frameless or with minimal frames. Architectural salvage pieces (dimension and texture) continue to make a strong showing as they can be placed next to art pieces on a large wall without competing for focus. Bright pops of color add a lot of interest to rooms that are otherwise neutral in tone (walls, floors, sofas). Subject matter is ranging anywhere from bold modern abstracts to images of your pets. Increasingly mirrors have joined the 'art' category with unique offerings that are beautiful as well as functional.
Estate sales are a great avenue to find vintage art that can't be bought in stores. Original pieces from local artists are also a great option - even without art fairs this year, many artists are selling their work online at reduced prices. Online sites abound as well, with enough options to keep you scrolling for hours. Whatever the source, the art you display is an opportunity to express yourself so don't feel rushed - take your time until you find a piece that speaks to you.