1. Log into YouTube.


2. On the left side of the screen click on "Your Channel."


3. Click "Customize Channel" at the top of the screen.


4. Under the "Layout" tab you can add a video that's already been uploaded to your channel as a trailer that will automatically play when non-subscribers go to your channel.


5. There is also an option under the "Layout" tab to add a featured video that will automatically play for subscribers when they go to your channel. It will only automatically play once for returning subscribers.