The pantry started out looking like this, earlier in the year. Not bad, but it was a mishmash of things and it got to the point where I started just shoving things in there, knowing that I was going to be reorganizing later.
I did a bit of a purge mid-year and it was looking a bit better, but still needed some work (a lot of things got moved out to the black, metal shelf in the garage).
I emptied each shelf and gave them a good wipe down. Then, I assessed each area to determine how to group the items. I found that putting like-items together made it easier to find things. Also, I decided to use the upper shelves (since it's harder for me to reach) for less-used & seasonal items and also to put less-used items in the deeper part of each shelf.
The white wire basket shelves above - the baskets slide out so I get full use of the deep pantry shelves.
As you can see, I used lots of baskets, bins, and containers. Some of the baskets I used have handles, which makes it easier to pull them out to reach stuff in the back.
Here's a closer view of the bottom cabinet with the baking supplies. I used wire shelving to be able to use as much space as possible. I also used my label maker to label the containers.
I also ended up trading out some of the items in the pantry with another cabinet in the kitchen. The trash can is now in front of this cabinet, so I was having to move the trash can each time to get in there.
This little cabinet was holding appliances that I didn't want to get rid of, but hardly use. It used to hold my hand mixer, rice cooker, and toaster, so I moved those out onto the bottom shelf of the pantry (3 pictures above) and moved some other hardly-used items. Now, I won't have to move that trash can out of the way as often.
After a few tweaks, I think I've got this pantry re-organized just the way I want it. It doesn't look as pretty as I'd like, but with it being so deep, function was the main priority.