The first time I applied to a gallery, I included portraits, landscapes, and still lifes, framed in a multiplicity of styles. My work was not accepted, but the gallery manager was kind enough to give me some advice: develop a cohesive body of work.
From my voracious reading of art books, I knew that one way to do this was to work in a series. But I didn't want to work in a series. In my mind, working in a series equated to backtracking and repetition. Ugh. There were so many, many things to paint, and having come to it late, I was striving to catch up. I didn't have time to waste.
Oh, how wrong I was! Working in a series is not about repetition, it's about deep-diving. Settling in and taking some time to explore the corners or your idea. Each successive piece illuminates and defines the original concept in a slightly different way.
It's not repetition, it's subtle shifts. Nuance attracts me, like a moth to a flame.
Here are a couple of examples of recent series, both of which happen to be groups of three... not a requirement!
And for a totally different spin on a series: