Backpack Organizers Keeping it Sane

Hey all, what do you use to organize your packs?

For example, I use a 22l daypack for most high peak day trips. I have 3 or 4 plastic bags to separate food, gear I may use, gear I hope I won't use, and first aid stuff and TP, moleskin, etc. Suppose I could combine all except food into one bag, what is recommended? What size for a 22l? Compression or no compression? Tired of the plastic, and tired of random messes too.

Thanks!

(if we want to discuss winter or multi-day trip, use a 48l pack, same scenario as above, plus a plastic bag for clothes, and another one for dirty clothes. Too much! Oh and add one for garbage.