I can't over-emphasise the importance of having a shopping list. It avoids last minute panics for all sorts of reasons. Not only for food - I find adding things like hardware (a 3M hook for holding clothes, batteries, all that sort of stuff) means that my decluttering gets easier over time because I actually follow through on jobs, rather than thinking "oh, I haven't got a hook to put there, too bad".
Do you need to buy or print or copy more shopping lists/notepads? If so do it now.
Do you have a designated place for your shopping list so you (and whoever uses the last of the peanut butter) can find it? If not I recommend putting them on the back of the pantry door. If you don't have a way to clip them to the door safely, add an adhesive clip to the shopping list, or screw a bulldog clip to the back of the door. Take a few minutes to do it now, it will save you hours down the track.
If you don't have a shopping list yet my mission is to convert you. A lot of kitchen clutter happens because you get to the supermarket, aren't sure if you have enough of something, and buy it 'just in case'. Hey presto, a cupboard overflowing with spaghetti, and no toilet paper (or in our case, a lifetimes supply of toilet paper, at least it was until the toddler decides to find out how much it will take to fill the toilet).
Having a shopping list makes you more confident that you have everything you need, and cuts down on costly unplanned eating out or takeaways.
For starters find some blank paper and put it on the fridge door, with a pen in a cup on top of the fridge to write with.
If you'd like a sample to print out which makes it easier to plan and shop, print this list, fill it in to look like this template (with the aisles in your supermarket and suggestions of what you buy regularly), and copy a stack. Then every week you can just fill it in like this one.