kind of an ambiguous question, depends on how long your songs are.
we have 6:30 songs, and a 2:30 song with many in between. we have 28 songs , all original. We plan our sets accordingly.
We have 2 songwriters so we try and alternate between them as they sing their own songs.
Got some 3 band shows coming which I love, we do one set of 45 mins, easy peasy,we switch songs regularly according to loudness of gig. We go from all acoustic to rock band mode.
Opps. forgot to say, 10 songs for a 45er