Paint Technique: Colorwashing
Materials and Tools:

white athletic socks
blue painter's tape
paint
paint tray with liner
long level
pencil
acrylic craft paint
Steps:
1. Use a level and light pencil to mark the desired area you plan to add color to, and then tape-off around the outside of the box.
2. Dilute a small amount of paint with water (two cups of paint to 1/2 cup water) in a paint tray and stir well.
3. Dip the tip of the sock into the paint and dab the excess off. Use circular motions to fill in the taped-off area, creating soft swirls of lighter and darker color. This variance is what gives the washing technique so much character. If desired, add to the technique in places that seem too light to make the overall appearance as even or as mottled as you like.
4. Remove the tape, and then outline the box using a small brush and coordinating acrylic craft paint.