It turned out to be really easy (after an hour of searching):
Step 1: Choose the first video you want and grab the embed code from YouTube.
Step 2: Add the playlist parameter after the first Video ID.
Step 3: To add to this embeded custom playlist, simply include the ID for each additional video separated by a comma.
Step 4: Feel free to include the usual &rel=0 (this makes it so YouTube doesn't recommend other videos once yours are done playing). And if you want to show all the videos in the playlist on the start screen, include &showinfo=1 (play with this one to see what it does).
Here's how my first attempt turned out:
I created it to show off some of the Assignment 1 samples from my free Filmmaking 101 course.
Your Media Production Mentor
P.S. If you are totally new to YouTube embedding, keep in mind:
1. The Video ID is (currently) a string of 11 letters, numbers, or other characters, like: 7XUdN1Q_v-0. If you're watching a video, it's typically the last string of random stuff in your browser's URL bar: http://www.youtube.com/watch?v=7XUdN1Q_v-0
2. When adding extra parameters to your YouTube embed, remember that the first one begins with a ? and all the rest start with an &. Basically, you're telling YouTube: Play this video, oh, I don't want you to show related videos and build me a playlist and start playing the video automatically, etc.
3. Anything else not making sense? Just ask!
*This tutorial will also be useful if you want to know:
- How to make a sharable non-public playlist containing unlisted YouTube videos
- Step-by-step instructions for creating unlisted playlists for YouTube
- How to add videos to a playlist without creating one in your YouTube profile
- ...and more!