Last year, I had one tub with a variety of worksheets in it for substitutes to use incase I had to call in sick. However, I felt it wasn't very organized.
I changed this problem by getting a 3-drawer organizer and labeling them: ELA, Math, Science/Social Studies.
Next to my Sub Tub, I have my classroom schedule, list of students, explanation of rules/procedures and 3 days worth of student work packets (incase my students need to be split-up into different classes, if a sub does not show-up).
On top of my Sub Tub, I have a basket filled with incentives (behavior tickets for the Treasure Chest drawer held on Friday and stickers) and a red bag with first aid supplies (band aids, contact solution-for teacher use).