From @read.it.and.sleep on Instagram

☆ a book for each letter of the alphabet (j, k, q, v, x, and z can be anywhere in the title, "a" & "the" as the first word don't count)
☆ a book with a color in the title
☆ a book with a number in the title
☆ a book with a name in the title 
☆ a book with “the” in the title (not the first word)