I watched a YouTube video by a US Doctor who showed how to wash shopping in a sanitary way. He washed down his surface then split it into two sides, the side for unwashed food and the side for washed food, he used a disinfectant spray on a cloth. It was similar to what I already do however I picked up the (simple and obvious once you think of it!) tip from him that you can take things like cereal, multipacks of things out of their original packaging, throw the outer package away and not have to worry about what is inside. So we always end up with a huge pile that goes straight into recycle bin then we always mop and wipe around afterwards.
Fruit and veg is put in the sink with slightly soapy water then washed and rinsed, same with milk deliveries.
I'm shopping for two other households too (parents and in laws) and do it for all, can be a lengthy process but it actually helps us feel as though we have some structure to our week (regular delivery slot) and gives us a sense of achievement when it's done! We bag there food into fresh bags and use sanitary wipes when holding the handles as we drop them off to their doors (distancing before they collect). It works well.
One of us opens the post and washes hands straight after, most post binned immediately or shot into cupboard awaiting filing. You can presume a lot of letters have been put in envelopes mechanically so letters inside the envelopes are not a huge risk, same for anything that may have been packed more than 3 days before (general rule of thumb is that 3 days is the longest Covid can survive on surfaces in regular, non-manufactured conditions).