I'm going to try and submit to agencies that have previously rejected me. Some agencies say that if one of their agents passes on your work you're free to submit to one of the others, and it's those agencies I'll target. I've decided that if I can't get an agent by the end of the year, I'll ditch agencies and try submitting to publishers directly. Big publishers don't take submissions directly from authors, but smaller publishers do. That may wind up being a more viable path forward.