Daily Paintworks's White on White challenge using Mary Van Arsdel's photo at Paint My Photo. "White on white" seems to be cropping up everywhere I look ... As usual, there are some really great interpretations of the challenge at DPW.
My own personal spring challenge, every year: daffodils. I started this without planning or drawing, just painting the flower shapes. I felt I had to add the darks, and now realize I need to bring them (or some other color, a background?) out to the sides ... and also to break up the line of flowers on the left: that's what happens when you don't plan!