I bought these and they're great for random stuff, plus you can see what's in them.
In one I have chapstick, tape, bandaids, some pocket warmers, aspirin. In another I keep sharpies, divot tools, ball markers, and whatever else.
Nice not having stuff floating around your bag.
I also like big containers, I find that separating things into smaller containers in them is the way to go. Like clear zippered containers like these can help keep yarn both safe and organized.
Black bags on the right are pack-it XS packing cubes from Eagle Creek, plastic ones in the middle are these cheap cosmetics bags from Amazon