This article explains how to create your own template in Google Sheets when one of the pre-built Google Sheets templates doesn't work. You'll need a Google Account to access Google Sheets. Sign in to Google Sheets with the same account you use to access Gmail or YouTube.
A custom Google Sheets template contains information specific to the spreadsheet you want to create. To create a custom template, start with a spreadsheet file that contains the information and formatting you want to use in the template.
Create the spreadsheet file in a spreadsheet program, such as LibreOffice or Microsoft Excel. You can even create the spreadsheet in Google Sheets, either from scratch or from the Template Gallery. Simply open one of those templates and edit it to your liking to fit your project.
To keep your custom templates organized, create a folder that contains only template files.