Add everything up first
If three recipes each need an onion, buy three onions once, not one each time. WeekTable adds the whole week together and scales it to the number of people.
Sort it by aisle
Fruit and vegetables, meat and fish, dairy and eggs, bread, the cupboard, world foods, spices, frozen. You walk the shop once.
Check what you already have
Oil, salt and the spices most kitchens keep are listed apart, so you only buy what you need.
Keep the rest
Packs come in set sizes, so some will be left. Tins, rice, flour and spices keep for the next week.