Facebook campaign structure is comprised of 3 levels of setup: 

• Campaign
• Ad Set
• Ad

On every level you have to tell Facebook things like: budget, schedule, placement, targeting, creatives and so on. 

Today we’ll be focusing on ad set level, more specifically on ads placement.

When it comes to placement, you can choose between 2 options: Advantage+ Placements and Manual Placements.

If you opt for Manual placements, well, you will have a large variety of options you can choose from:

1. Feeds
    
   
   
2. Stories and Reels
   
   
   
3. In-stream ads for video and Reels
   
   
   
4. Search results
   
   
   
5. Messages
   
   
   
6. Apps and sites
   
   
   

What are the best practices for aspect ratio?

• For feed placements: We recommend square 1:1 for images and vertical 4:5 for videos.
• For Stories and Reels placements: Most people hold their phones vertically so we recommend 9:16 to capture the whole screen.
• For video carousel format: We recommend square 1:1 and consistent ratios for all videos in a carousel.
• For in-stream video: We recommend horizontal 16:9 to fit the videos the ads are in.
• Meta Audience Network placements: We recommend vertical 9:16.
• For Instagram Shop: We recommend square 1:1.

Some things you need to take into account when setting up Reels, especially on Instagram. 

The best practice is for you to upload Reels of 9:16 ratio. However, you might find that your story format reels will be cut off, as they are displayed in-feed as well. Keep in mind that you must deactivate Instagram reel placement, if you don’t want to have them cut. Instagram Reels can be seen in 3 places:

1. Feeds
2. Instagram explore
3. Reels tab

So, where do you want your ads to appear?