Reduce routine shopping time by
Make a list of items you shop all the time
Shop at a fixed schedule e.g. every tuesday, every 4 weeks, every first tuesday of the week.
Shop the items in a fixed order (possibly matched on you list). Note: Most stores change the order almost never and the order is part of the customer retention program, so you should be aware that this will bind you to the store.
Choose a weekday and time where the supermarket is mostly empty (e.g. in the morning instead of on saturday or in the evening when it may be crowded)
Do the shopping together with other persons to batch larger amounts and/or use transporation together (a car)
Buy a larger fridge (possibly a large top loading one in the basement (the top loaders are much more engery efficient) to reduce the number of times you have to go shopping.
Freeze some food not customarily frozen: bread/buns, butter, cut cold meat (it may affect the taste)
Use a a grocery delivery service. But note that it may not save as much time as you think:
You can still buy fresh fruits and vegetables etc. more often e.g. bi-weekly. You can use that time to do fun shopping with a mostly empty basket and unhurried.
Some more context for this can be found in the following scattered comments:
Personal example:
We used to shop every five weeks with a pre-filled checklist for 6 persons. In total about 4-5 shopping carts full (I heard the german carts are relatively small compared to the US ones). It takes 3-4 hours total. Note that this includes >1h to store everything away (e.g. unpacking vegetables, fruits, unpacking boxes, reordering fridge). What remained were short weekly single-shop trips to buy milk, fruits, bread and a few other items.
I'd guess that compared to shopping every two days as my mother used to which took at at least 1h each time (whatever the amount purchased) this probably saves about an 1.5 hours each week.
And it is cool.
This is an extension of a comment I made that I can't find and also a request for examples. It seems plausible that, when giving advice, many people optimize for deepness or punchiness of the advice rather than for actual practical value. There may be good reasons to do this - e.g. advice that sounds deep or punchy might be more likely to be listened to - but as a corollary, there could be valuable advice that people generally don't give because it doesn't sound deep or punchy. Let's call this boring advice.
An example that's been discussed on LW several times is "make checklists." Checklists are great. We should totally make checklists. But "make checklists" is not a deep or punchy thing to say. Other examples include "google things" and "exercise."
I would like people to use this thread to post other examples of boring advice. If you can, provide evidence and/or a plausible argument that your boring advice actually is useful, but I would prefer that you err on the side of boring but not necessarily useful in the name of more thoroughly searching a plausibly under-searched part of advicespace.
Upvotes on advice posted in this thread should be based on your estimate of the usefulness of the advice; in particular, please do not vote up advice just because it sounds deep or punchy.