Now that we know pretty much how axes work, let's see where you can be even more efficient! If you're not sure how axes work, you can read up over here!
When you have to manage multiple ad sets, or creatives, you will be happy to use filters to find exactly the one(s) you're looking for!
Filters are available on each side, both for ad sets and for creatives, and will display only informations that you have used in your campaign. (For instance, you won't find Male and Female options if you selected only males in your campaign.)
The same works for Creatives:
You will always have the option at the top to filter in only items that have no axis assigned to it, to make sure you're not missing anything!
You can see in the screenshot above that more information is displayed on top of the Creative. This is what you'll see when you toggle on the "Show Details" button. This should help you make sure you're linking all creatives and ad sets properly, even when they look the same!
When you're filtering, you can then use the [+] and [-] button to select, or un-select all of the items displayed after filters!
You can also use the Facebook logo next to the "Show Details" to change the preview type of the creatives: