One of the easiest things is to get a large shelf and put it in the garage, but let me warn you...this is not the best! Garage temperatures swing wildly and heat is destructive to most foods. The lifespan of your stored goods will be dramatically lowered if stored in the heat of a garage. Cool temperatures are better, and even better are steady, cooler temperatures, like inside your home.
Some people convert unused closets.
Some folks store extra food under beds.
You can pair up a library with food storage:
Wherever you can find room is a good place for food!
Remember to rotate your stock on all stored foods and eat what your stock. Only honey lasts forever....wheat can be stored about 30 years if kept correctly. There are a few other long lived foods, but not a lot. Most canned foods last 3-5 years, though can last longer if stored in optimal conditions. Know the lifespans of your products. Use a Sharpie to write the purchased date on your items to help you rotate them easier. You MUST actually use your food storage. Consider your pantry your first grocery store. When you run out of ketchup, go to your pantry and get the next bottle. Next time you go to the grocery store, buy an extra, date it, and put it in the back of the shelf. The best way to build your food storage is to just buy two or three of whatever you are going to buy anyway.
Purchased canned foods can easily be rotated using a FIFO (first in, first out) storage rack. Making sure you move the older of your stock to the front when putting away groceries is essential! When you are storing bulk food, look into using mylar bags and oxygen absorbers or Foodsaver bags to divide them into usable portions. No need to open a 50 pound bag of oats all at once when you have repackaged it into 5 pound bags! You won't have to be stressed about eating it quickly enough, OR get sick of mush in the morning!
We'll discuss home canning more next time.