When I performed I would have a 'stock' list of forty or so songs to choose from--things I was current with and did well (at least as well as I am able). My first sets (in clubs or at other venues) was always one I 'knew' worked. After that, I chose from the rest and decided what to play based on the mood of the audience. The key is to develop enough stuff that satisfies you as a performer and the requirements of your audience.