This is for Jim who asked if there is a way to deal with the 85 min period with 7th and 8th graders.
I would do "altered books". When I did "altered books", each student would take a used book, and change the cover and the back cover and the end sheets, by establishing a theme and making art on those parts that establishes the theme. They would keep the books on a designated shelf. When they were done with their current assignment, they would go over to the shelf and pick up someone else's book, and make a double page spread in the book, based on the theme that was established on the overs and endsheets. The books were there all year, and available for students all year. In that way they had "choice" and an established theme to work with.