That will depend entirely on your economical situation. I usually manage my containers like this:
Gold - Shopping Bag
Lootable Items - Brown Backpack
Potions and Runes - Cake Backpack
Shovels, Picks and so and so - Red Backpack or Crown, (Sometimes even Demon)
But as I said before, organizing a backpack is not like a ruled thing. It's entirely up to you to do it your way. You could also skip items on time frame (meaning you only skip the things in the main grounds you are hunting) But if you really don't care, just mess it all up.
I only carry my backpack in messy ways if I'm on Pvp Mode (In every sense)