We’ve a narrow pantry in the the space under the stairs where most of our small kitchen appliances life when not in use. This includes the InstantPot and KitchenAid stand mixer.
As much of the meals prepared in the InstantPot are spice & herb heavy which tends to make the gasket smell spicy, we store outs with the lid upside down to allow the gasket to air out… and collect dust. YUCK! And of course, it’s just the most space-efficient to store the mixer bowl with the mixer.
All materials are stash - in fact, the circles were already cut in appropriate sizes from an abandoned bowl cover project. 
I just did the simplest (crudest?) hem around the circle, then zigzag stitched the elastic over the pinked raw edge. No lining, no interfacing or stablizer.
