The Trader Joe's near me took the most serious steps so far. They are limiting to 30 people in the store at a time and setup 'lanes' six feet apart for carts to lineup for checkout. When you checkout, they take the cart and have you stand back while they ring up and bag your stuff. When it's time to pay they back up from the register and let you pay and take your own receipt. I say these are the most serious steps because the other grocery stores near me haven't changed much of anything last time I went to them.
It was a little weird at first, but I am willing to go through whatever hoops to make the grocery workers comfortable.