Making sure that, as I finish one packet of something (rice, pasta, flour etc) and refill the storecupboard container (kilner jars) from the new packet in my stockpile - I immediately put the need for a new packet on my shopping list so I have one when the current one runs out.
Always having a few tins of things that I can make a dinner from - tuna, sweetcorn, Chinese beansprouts, tomatoes, ...rice, pasta, stock cubes etc. And long life things in the fridge - Lidl lardons, Lidl chorizo, frozen peas, natural yoghurt, carrots, etc (and always potatoes, onions, garlic in the cupboard). So if disaster strikes (snow, life gets manic and no shopping can get done, unexpected people turn up needing a dinner rather than egg/chips/leftovers......), I can manage.
Every few years, use up the bottled water that went out of date a few years ago, and buy a couple of fresh bottles for emergency use (I only keep about 2x2l bottles for utter emergencies - there's usually some warning to allow you to fill a couple of pots etc). Watering plants can be a good way to use them up if you don't want to drink it.
Always have a nightlight and some matches easily accessible in sitting room on mantelpiece - if the power goes out, you know the path to that and can figure out more lighting once you have 1 going.
Or a windup torch in the bedside locker.
Make sure you still have gas for the BBQ at the end of summer - we've cooked dinners on ours in snow and in powercuts in the past, just wrap up well to go outdoors!
And always have enough fuel in the bunker for at least 2 days of the stove/fire in winter - more if bad weather is looking likely.
Save the lint from the tumble drier, push into an empty toilet roll middle, and use that as a firelighter - great on scout camp, but also works well indoors! (And reduces waste at the same time).