One of the questions I always get asked in classes is - "how do you pick a theme?" This is a really good question. Usually themes pick me. Maybe the title of a book will suggest a theme. I actually shop for titles in the thrift shops and used book stores - or yard sales. Some titles are just irresistible. City of Bones, Born to be Wild, Surviving, Headaches. These are all titles I have used. The whole concept for these books sprung to mind as soon as I saw the titles. Now friends are saving books with interesting titles for me. Someone recently gave me the book Kiss of the Virgin. Hmmmm...... (Now, don't think you have to keep or use the title that's on the book. Sometimes I use a book because the size is right. I'm working on a religious theme in Jane Fonda's Workout book. )
Maybe you want to do a book about something in your life, or someone else's. I did a retirement book for a friend when she left the workforce. Romance can be a wonderful romantic theme. On the other hand, aging and death can also be strong themes.
Perhaps it is the lyrics of a song that will inspire you. Maybe it is a quote that means something special and that can be illustrated some way. Sometimes images themselves suggest a theme. Maybe it's a mood. Love? Tenderness? Anger? Political injustice? War? Family reunions? Chocolate? The Beach? Paris? Flight? There are more themes floating around out there than there are artists to do them justice.
My suggestion is to make a practice book first and not be tied to a theme. Just play with it and have fun. It may develop a theme by the time you are through playing with it. Maybe the images you choose to use will suggest a theme, or the colors. Perhaps the construction will develop into a theme. Windows? Doors? Tunnels? Folds?
Your themes can be as frivolous, or as serious as you want them to be. Altered Books give you total freedom and control. You are the artist. It will be what you want it to be. Relax and let the artist in you take over and see what you can do.