Creating collections is the first step to creating a playlist. But you can take your collections to a new level by customizing your playlist to play in the order you like. uvLayer plays the videos from top to bottom, if you're in stacked view, or they play from the upper left to the bottom right in the window view. There are a few different ways to accomplish this.
If you're watching a collection of videos as a playlist, you can change the playlist order as it's playing:
If you're watching one video or a collection of videos, you can also add more videos to the playlist:
To learn about re-sorting a playlist in the window view, see To re-sort your playlist from the window view.