Setting your Teams background to a custom image. How to change your teams background to a custom image for use in calls. 1. Click " Calendar " 2. Click " Meet now " and join a meeting with yourself. 3. Click " Effects and avatars " 4. Click " More video effects " 5. Click " Add new " 6. Select the image file with your chosen background and press "open" 7. ✅ The custom background will now be set as your default wallpaper during future Teams meetings, you can change it to other images by re-following the steps in this guide.