Here are the basics of how to create a slice.
1. Go to your slice manager (direct link here).
2. Click the “New slice” icon near the top of the screen:
3. Your slice will be created, and you’ll see the slice settings screen. Enter a title and (optionally) other information. (See here for more on slice settings.)
4. You’ll see the slice editing interface. Much of it will be grayed-out, because it doesn’t have any music yet:
5. At this point, you can do different things depending on your workflow. The main options are: