You can design and create a presentation and save it as a theme, to be reused as a template for other presentations or individual slides.
Below are instructions for creating a Present theme.
Once created, a theme will appear on the creation popup when a new presentation or a slide are created, allowing users to reuse the theme. Simply select its thumbnail to create a presentation using that template.
Present themes appear as separate entities to the presentations. You can browse for all themes available to you via the Browse page, by choosing the Themes option.