I click on the document pages from the Updox Workspace window, and use the "Next" & "Previous" buttons that appear at the upper right & left of the page to find where I should check or sign. Then use the pencil icon at the top of the page to enter the edit mode. A new page opens, with the mark-up tools at the upper left. There are tools for making checkmarks, arrows, circles, text entry and even a signature icon that inserts a signature that you've uploaded to Updox. I don't use that much any more for signing, since I can scrawl my signature with the pencil tool just as fast, and it looks more unique if you need to sign several pages.
I also customized the fax coversheet in Updox so that it has the statement "Text and signatures entered on the attached documents are electronically generated by the physician, and are not stamped", so I don't get anything faxed back about not accepting stamps.
Then save the document and click the send button to fax it back. You have to enter the patient's or facility's fax number in the Address Book first, no place on the send window to enter the fax number.
Takes about a minute to receive, markup and refax a form. And no paper to shred.