Somewhere I read that Seve practiced chipping coins so I got into it. I recommend it for sharpening focus on the exact point of impact where the blade must meet the carpet and coin near simultaneously, as well as your control of where to land the shot.
You can play it from wherever you want between your feet. The farther forward you address the coin the higher it flies. I like to use a cereal bowl about three paces away for the clinky sounds that reinforce the satisfaction of a good shot.
I think that once you learn the fundamentals of chipping this is an excellent practice drill.
Same theory as chipping off a flat piece of wood, which I would also recommend. You are trying to exact the bottom of the swing. This and the coin method provide immediate feedback.
In his instructional video titled the short game, after hitting a standard bunker shot I believe, he says let’s have some fun. Then hits a flop with a 3 iron.