From The Document Foundation Wiki
- Create a presentation that can be used as a template (including any master page customization you need)
- When the template document is complete, select ▸ ▸
- If you want to create your own directory to store your templates (recommended):
- Click Manage
- In the dialog box that appears, click a name in the left side of the dialog box, click ▸
- A new directory named Unnamed will be created and appear in the left side of the dialog box
- Name your new directory and press ↵ Enter to confirm the name, eg My Templates
- Click Close
- In the "Templates" window, under Categories, make sure your directory is selected
- In the field New document template, enter a name for your template;
- click OK