I've been prepping now for a couple years and have learnt a few things through making some mistakes.
Mostly being split between thinking long term storage and practical storage of food items.

What I mean by practical is foods I eat, Rice seems to be a big one for food preppers and that great if you really like rice, but I don't, at best I eat rice once a fortnight when I make a fried rice.
Sure rice is still a good prepping item as you can add cooked rice to many meals if you needed to add a filler, like campbells chunky soup in a can, if you wanted to add a bit more bulk to it you could add a cup of cooked rice, things like that.

So I keep 20kg's of rice aside just as a long term storage item, one day I will rotate that rice, maybe in 10 years time, cook it up and feed the chickens with it, even though they don't like rice either, I can mix a little in with their scraps.

Other foods I don't use that often is honey, I have a lot of honey stored but it's ok because honey last forever really.
Cheap brand name foods are another I don't like to eat, if I am to eat out of a can or packet then I want the good brands that still taste ok,
the most important thing to me is to rotate my food supply so I always have a reasonably fresh stock, so I need to want to eat the foods during normal times to keep the rotation going.

I've done a video I wanted to add here which is of my pantry setup, over time I want to expand on this video and show new additions aswell as how to cook from pantry supplies.
also what to do with excess qty's of things I like to stock, like long life milk, I prefer a particular brand of milk in normal times but have found having a stock of long life milk comes in very handy at times.
When the milk comes close to expiry I make a farmers cheese from it, which can be eaten fresh like ricotta or salted, rolled into a ball and dried outside for a hard cheese that's good too.

Anyway here's my first prepping video, hope to be adding many video's as I go including growing some foods, chickens, prepping for the vehicle and building materials that may come in handy come shtf.