Go to Setup

Search "Communication Templates" or go to Administer -> Communication Templates, then click Email Templates

Select "Jasmine Email Templates" Folder

Select the Email Template to edit by clicking the template name

Click the "Edit HTML Version" button to edit the template

Use the editor to update the email template

Use Merge Fields to pull data from the database to be added to the email when sent. Then copy and paste the code into the email template.

Use the Attachments' section to attach files (ie. PDFs, Docs, etc.) to the email template.

Click Save when done.