I have a key holder by the door. The kind that is attached to the wall. I have a net bag hanging off one of the pegs with my masks in it. Paper masks get worn 2 or 3 days and are then replaced. Cloth masks are washed every couple days also. No worn masks get put back in mesh bag until cleaned.
This is a good question. I’ll be interested in how others do this.
I also keep a few new ones in the car.

Baggie in my purse. Fresh disposable and cloth with filter.

I have seven of them hanging for each day of the week. They’re washable but I don’t wash them every week.

I keep mine in a baggy in the car where it gets very hot and sanitizes them.

I hang mine on the rear view mirror

I only have the blue paper masks. I just shove them into the glovebox in the car.

Triple thick cloth, they hang on pegs at front door. Cleaned when I return, in microwave for one minute in a wet paper towel.

I have about 8 made by a friend. I wash them after use and hang them on a rack above my washing machine. Keep a couple in the car in case I forget.

Mine are just on the arm of my couch.

I have started putting sticky jewels on mine so the aren’t so ugly.