Remember the Milk may have tons of GTD users (I am one of them too), but true to its name, I suggest a method that has worked for me to remember the milk always.
There are plenty of apps that support shopping lists and to do lists. But none come close to the flexibility and usability of RTM. My system of maintaining shopping lists is as follows:
Step 1: send an email to my RTM email address as soon as a grocery item gets over at home.
example - "Onions 1kg @Carrefour #Shopping".
If there are many items to be added then you can send many items to the RTM import email address with subject line: Shopping
Step 2: Once you arrive at Carrefour (or any other shopping destination), pull out your location based list (you can bookmark the m.rememberthemilk.com Carrefour location page and pull it up when you are in the store or choose the location link in the app)
Step 3: Complete the "task" line item when you pick up items from the grocery store.
Step 4: Over time, there may be items which repeatedly go in and out of your list, so create a smartlist called "Pantry" with "list:Shopping and status:completed and location:carrefour". So, next time you have to add an item, look up in this "Pantry" list, if you have already bought this item. Check this item and click "Uncomplete". This will make sure, the item goes back into your live shopping list.
Alternatively, you can maintain a tickable checklist on evernote with all possible items in the list and add a reminder for shopping days, so that you can see the list when you are in the grocery shop.
Always "Remember the Milk"!
Posted at 4:01pm on June 20, 2013