1. Go to Marketing > Email > Templates and click + Add New.
2. Enter a Title and pick a Starting Layout (DIY, the drag-and-drop layout, is the default; any custom layouts installed for your account are listed as (Client Custom)), then Save.
3. The designer opens with a Live Preview of an empty email. Click Add Module (or hover a module in the preview and use the + buttons for Add New Module - Before/After) and pick modules from the categories Header, Content, Buttons, E-commerce, General, Social and sharing, Footer.
4. Click a module to edit its settings in the side panel and press the panel's save; use the hover toolbar to Edit, Clone, Move up, Move Down or Delete a module.
5. Use Settings to change the email's title, colours and widths, Preview to open it in a new tab, and the desktop/tablet/mobile icons to check responsiveness.
6. Switch on Save as Template in the top bar if you want this design listed as a reusable template.

A How to edit button on the Templates page opens a short video tutorial.