You can use this sample project as a template for your own.
Here are a few of the designs I found to inspire my own bookplate design.
I designed mine in Illustrator so it would be vector and scalable to any size. I wanted my bookplate to be for my family's library of books, so I choose to use our last name instead of just my own name. And since I love doing handlettering I wanted to incorporate that a little bit into the design too with the large B.
Here is my final design with texture added to both the bookplate and the background. I did 2 layers of background texture to get the extra detail and different sizes. Now to add it to everything I own :)