I have made two different bookplates for my own collection. The one on the right is the first one, made during high school. It’s the coat of arms of my ancestral Scottish clan, the Mackays. They were both drawn in scratchboard, my favorite medium in high school and college. 
The cornucopia for image connoisseurs, called “Dark Roasted Blend,” has an inspiring collection of bookplate or “ex libris” art, some funny, some macabre, some poetic, some extravagant.