Do you use cozies/ covers for any of your stuff?
Yes!
If you do, what do you use them on, and what made you decide to do it?
I use shrunken wool and I do it to hide anything I don't like the look of, either because it has a pattern on it or is made from plastic and looks cheap.
Did you make or buy them, or were they gifted to you?
Make. The wool was gifted to me but not for this particular purpose
Do you love or hate them? And why?
LOVE mostly because they make everything look cozier
What fabric(s) are they made of?
Preshrunk 100% wool
Do yours have some means of securing them, at the bottom? If so, what, and do you like that feature?
The wool goes on like a sock or sweater so its own tension holds it in place, no securing needed.
Is there anything you'd change about the ones you have; what, why, and how?
Nope, they work great and most are no-sew projects as I can just tuck the cut edge under. I have gained the ability to quickly match a shrunken sweater's neck, arm or body to an item in my house - a strange skill I have developed.