You can automate the creation of job offer letters or invoices in Google Docs using Zapier's workflow automation feature, which allows you to create Zaps that send information from one app to another. To do this, you need a Google Doc template and a Google Sheets spreadsheet with data to populate it, as well as an account with Zapier. You'll set up the trigger by connecting your Google Sheets account to Zapier and selecting the spreadsheet and worksheet you want to use, then map the data from your Google Sheets spreadsheet to the fields in your Google Docs template using Zapier's mapping feature. Once you've customized your action, you can test it and generate sample data to ensure everything is set up correctly. With this automation, you'll never have to manually create templates or copy and paste information into specific fields again, saving you time and reducing errors.