I belong to WetCanvas, an online painting group (www.wetcanvas.com) . Each weekend they have a "Weekend Drawing Event". Someone hosts and provides photos to use. You can then use one (or all) of the photos to do a work in any medium of your choosing. I did an 11 x 15 watercolor. I really prefer using my own photos for my paintings. I think it gives me a greater connection to the subject, and then the painting comes out better. But I enjoy participating in the weekend event. It makes me try different subjects that I wouldn't usually paint.