If you are using coupons, take a couple of minutes before and after checkout. Make sure all of your coupons are together and relatively neat to make it easier for the checkout guy or gal. If you have any items that are free after coupon, put them towards the end of the line of groceries to make it easier for the checkout person to write in the cost of that item. After checkout, move out of the way of traffic and double check your receipt. I can’t tell you how often I find mistakes, either mine or theirs, on my grocery receipt. It is much easier to go to the customer service counter while you are still in the store to get the problem fixed.
If you happen to be completing a tax exempt order, make sure you have all of those items grouped together. I often have two transactions—our order and the church’s order. Have cash ready for payment and the tax exempt form available so that you can record the ID number on the grocery’s tax booklet.