1. Go to Weekly Subscription Groups (/admin/plansgroups) and click Add new (the How to Create a Subscription Group button plays a video).
2. Optionally click the Group Image box to upload a picture (saved as JPG; shown on the group tile).
3. Enter the Name (required — otherwise "Name empty").
4. Optionally pick Categories (multi-select, grouped by category group) to restrict the meals offered.
5. Choose the Category Union rule and, when editing later, what Changes in this plan will affect.
6. Leave Is Active? on.
7. Enter the Description ("Shown to customers on the subscription creation page.").
8. Click Save; a Done! banner confirms.

Then open each plan and select the group in its Group dropdown.