Waxing and Waning

As an artist I find myself often flitting from one piece to the next. I look at my work bench and see several 1/2 finished pieces, some have been sitting there for a while. Glass may entrance me this week but next week it may be metal, sometimes the shift lasts weeks or even months. I never know what's going to draw me back to the other or when. While I never truly move completely away from either medium I do swap back and forth a lot. It makes me wonder if there is a more efficient way of working?