Clear It Out
Clear your pantry completely. Take everything out so you can see what you've got. Chances are you have a lot of multiples in there, things you bought again and again because you didn't know you had one already. You might even find the soup pot you've been looking for since you moved in!
Put everything in like groups, all the canned goods together, all the bread foods together, all the snacks together. As you're grouping, check food for freshness and look at expiration dates. Throw away anything that is past its prime. You'll reduce clutter and maybe even keep yourself and your family from getting sick.
Use The Space
Look inside your cabinet, and think through how you want to arrange everything. Containerize your groupings to keep them together and more easily accessible when you put them back into the pantry, and put any loose food into airtight containers to keep it fresh and easier to grab and go. Using stackable containers helps keep your pantry neat and your food easy to see and access.
Put It Away
Now that you've sorted, grouped and containerized, put your food back into your pantry. Don't be afraid to move things around - it might take a little trial and error to figure out the best fit. Remember, keep the things you use frequently at eye level and towards the front. If your pantry is deep, step organizers can help you see what's at the back of your pantry shelves.
Once you've decided where everything should go, keep it there by labeling the container or spot properly. Changing a container's contents? No problem. Change its label, too.