My son and his best friend had a joint birthday party when they turned 1 . . . they are 3 days apart in age . . . so his mom and I chose Legos for the theme.
I bought the box at Pamida for cheap and painted it then added the "studs" by cutting cardboard circles and gluing 2 together for each stud.
For the cover of the book I covered cardboard with patterned paper. The little lego accents on each page are just cardstock strips with eyelets set in. And I bound the whole thing on my Bind-It-All machine.
Love me some mini books!