When you open a new document with File - New, a blank document appears based on a LibreOffice template. You can edit, modify, or replace this template so that the new document contains your customized Styles or other contents.
You can define document templates for each LibreOffice application.
Save the document by choosing File - Templates - Save as Template, then enter the template name, click the Set as default template checkbox, and save in the My Templates category.
The next time you open a new text document, the new document will be based on this new default template.
Use Filter to select the type of document.
The default template is marked with a green check mark. Right-click that template and choose Edit.
When you open a new document, the modified default template will be used.
LibreOffice provides built-in presentation templates, which cannot be edited, renamed, or deleted. To modify a built-in presentation template, open a document using the template, modify, then save as a new template.
LibreOffice provides built-in templates for Writer, which cannot be edited, renamed, or deleted. To modify a built-in template, open a document using the template, modify, then save as a new template.
Right-click on template to be made default, choose Set as Default.
Choose File - Templates - Save As Template, then enter the template name, choose a Template category, and save.
Right-click on the template to be modified, and choose Edit.
You can save any document as a template by selecting "Template" file type in the Save dialog. To access the template from the Template Manager, save the template in the User Paths directory specified for Templates in LibreOffice - PreferencesTools - Options - LibreOffice - Paths. It is often easier to save a document with File - Templates - Save As Template, because it automatically places the template in the appropriate directory.
The Template Manager is the preferred method for working with templates. File - New - Templates and File - Templates - Manage Templates are equivalent for opening the Template Manager. Ctrl+Shift+N is the predefined shortcut key.