What are you most proud of? Finishing the "painting". What advice would you give someone starting this project? Start fairly small, a 5" x 5" square design will take plenty of time. I would say if you can spray paint the eggshells, do so, otherwise you'll be painting by hand. Have toothpicks handy to to widen the "grout" lines (by adjusting eggshell position). Try airbrushing the eggshells for a more subtle effect.