1. Upload your PDF document in the appropriate Document folder (Quote, Sale, Project).
2. After you generate your quote (or other) for the customer via the Print/Email button and it is attached to the record, click the 'Send with DocuSign button.
3. When you are on this screen, and the customized quote (or other) is already attached, click on 'Add Document', and select 'Document' from the drop-down list.
4. Select the appropriate folder that your PDF document is stored in, then mark the checkbox to add it to this Docusign Envelope. 
5. The additional PDF document will be added to the envelope: 