You were bored. You had nothing better to do. You were doodling. Though doodles are just random drawings and are usually thrown away, often times there are some great doodles you should keep and use as a reference.
Face it, people have their slumps at least once and this is a great way to jumpstart that void and get the creativity going once more during those tough times.
To the right is a doodle I did years ago. It was a random drawing I did of some females and they turned out pretty well, imo. What I liked about it was the clothing that I randomly drew on the two girls at the bottom part of the page. One girl is wearing a dress and another is wearing pants and a trench coat of some kind. I liked that trench coat design, so I kept this doodle, and I plan to use that design some day.
Again, keep all or select ones you like or shows a good idea or design that you’ve made. Keep the ones you made at the margins of your notes and cut them out too, if you must.
To keep them all organized, put them into folders, binders, or just draw in one specific place for your doodles such as a sketch book. For select doodles that I cut out, I pasted them on a blank paper along with other cut doodles for easier reference. I then put those papers into a sheet protector and then into a binder.
A sheet protector is a plastic paper holder like card holders which comes in different weights from economy to super heavyweight and transparencies from semi-clear to diamond clear. For this purpose, a semi-clear, economy weight sheet protector is the best and cost-effective but if you prefer-and if you have the money-, diamond clear, economy weight sheet protector works just as well. They usually come in packs of 25, 50, and 100. I use Avery sheet protectors which you can most likely find at your local office store.