Rubber bands are pretty useful. I like to buy a cheap assortment bag to have on hand. One way that I use them is to keep bags closed. You know, those plastic bags that lots of gluten-free flours and mixes come in. Especially if you only use a small amount, it can be difficult to use a clip.
For certain bags, rubber bands work great for keeping them closed. I’m not talking about squeezing the top of the bag together and closing it by wrapping a rubber band around it a hundred times. I’m talking about folding in the corners of the bag top, then folding the top down once or twice, and wrapping the rubber band around the entire bag, top to bottom. Like this:
The right size rubber band keeps that bag closed and is not easily knocked off like some clips.