I googled covers for the the books I read, and printed out photos for each book. I haven't written a review for every book, but instead written more about the kind of books I read and my most and least favorite.
The format is 9x12, but for the last page I cut a 9x3 strip from a full size all 3x4 pockets page protector.You see the page folded out below, and in the photo below that the last page is folded in, to reveal the back side of the cards. I only had one of those Book Review PL cards, so I scanned it in black and white and reprinted the image.
The top middle card here is a bonus card that Brandi Kincaid Thompson sent me, when I ordered a portrait doodle from her Etsy shop last summer. Love it!