Way too often! Usually once a week because we need the produce. Sprouts has double ad Wednesdays which I like to take advantage of. We usually stop at Trader Joes, then Sprouts, then finish up with a trip to Costco (all on Wednesday). Sometimes on Mondays when my older two have a gymnastics class I will quick run down to Smiths (one of our "main" grocery stores) with just the younger 3 and grab a few things then too. I always have a list, but will usually also grab a few things extra as well.
I put the rather important things on the list, then I wind up forgetting about it and not getting half the stuff we need. I try to do the main shopping trip once every two weeks, and then usually wind up going to Save-a-Lot somewhere in between to get a gallon of milk, or more bread or vegis.
I go on payday-- every two weeks. My list is extremely important. I try to plan meals around sales and then add anything else we need to that.
About once a month I try to hit Aldi for things that are cheaper there (baking supplies like vanilla extract, fresh berries, cereal are big ones!).
I go SO OFTEN! I'm not kidding at least 3x/week. I like getting fresh produce, and I will go through some stuff so fast - especially berries and avocados. And I shop at so many different places. I go to one store for produce and eggs, the health food store (right beside it) for whatever the first didn't have, as well as some dried goods or specialty items. Then I also go to my SIL's store for extra produce (it's further, so that's not as often) and then I go to the main supermarket for berries, dairy and snacks since they are cheaper there than the other stores/have the ones that I want. And on top of that, we have a farm delivery for veggies once/week. I always think I should be able to buy enough food for an entire week, but we always run out of something (or lots of things). I have NO clue how people shop 1/week or 1/2weeks!
I go whenever we start getting low on important things. I take a list but that's just of the 'must have' items. I improvise a lot. I'm not all into meal plans, so I just buy stuff and then put it together later. LOL.
I go once a week for "everything" and usually have to go midway through the week for more produce. Like....my kids can eat 16 bananas in 3-4 days. Buying any more than 3 bunches at once would be ridiculous! So usually mid-week I will get more fruit and veggies if needed, and usually more milk.
I make a list. I try to meal plan beforehand for the week so I know what I need, especially because of DH's new diet.
I shop at Superstore for groceries, and I make a Costco run once a month for diapers, wipes, and bulk items - like big boxes of frozen chicken breast.