Your sketchbook is very personal statement. It can be autobiographical or tackle concepts like solitude, party, love or war.
Inspirational Ideas:
Start with the lyrics of a song
Research a topic you are interested in
Design simple pages
The cover
The binding
Have a page extension
Include a see through image
3 or more 2 page spreads on gessoed pages
Text that is personal
A collage
Drawings
Photographs from old magazines
Doors
Secret compartments
Respond to prompts
Sketchbook Assignments
Self-Directed & Self-Motivated to experience the search, the use of feeling, sense, and past experience as a means of discovering what is immediately intriguing and useful and what serves to create those kinds of visual events that are satisfying and alive. The sketchbook is also used for required research and planning for class projects.