Choose one activity
Build the kit around drawing, paper collage or another specific activity. A general box of everything is harder to use than a few materials suited to the next project.
Keep the contents visible
Use a simple pouch or shallow box. Include only items you can identify and put away easily. Store sharp tools safely and keep materials away from children or pets when needed.
Reset after each session
Put usable scraps back in one place and replace anything that has run out. Add a small note naming your next idea. Opening the kit should make starting easier, not create another sorting task.