I use so many that are already posted here. I love PIZZA boxes! My godfather's people love me. They looked at me funny the first time, but now they just ask what size and how many I want. LOVE IT!
I use plastic stackable shoe boxes to hold my scraps FQ and smaller, they are assorted by color.
I use a plastic thing you put wet dishes in to dry in your sink, I have it on the bookcase in my sewing closet and it holds all my rulers.
You can use a lot of household items when handquilting. I have a hard time holding on to a hemostat to pull the needle out. I like using balloons. My kids are trained. They see one that has popped and pick it up for me. Works great to pull the fabric through.