You write the same practical directions repeatedly, but each message needs a different name or date. A Gmail template can keep the stable wording ready. Inserting it still leaves you with a draft to review; saving a template alone does not set up an automatic reply.
Save only the reusable part
In Gmail on a computer, open Settings → See all settings → Advanced. Enable Templates and save the changes. This feature is documented for the computer version, not the Gmail mobile app.
Compose a draft containing the text you want to reuse. Under More options → Templates, choose Save draft as template → Save as new template. Give it a name that describes the task, such as “Appointment directions”. Keep a separate copy of important wording: the help page says a deleted template cannot be recovered.
Finish a new draft before sending
Start a fresh message and choose the saved entry under Insert template. For example, “Your appointment is on [DATE] at [TIME]” deliberately leaves two fields to fill. Replace both, read the message in full, then check To, Cc, Bcc, subject, links and signature. A template name is not proof that today's details are correct.
Updating a saved template uses the separate overwrite option. Check that you selected the intended entry before saving. If you only want manual reuse, leave automatic filter replies unconfigured: those require their own filter and matching rules. No email was sent or account setting changed for this example.