You start by hand-signing your signature on a blank white sheet of paper. Make the signature as large as possible (several inches wide). Once you've done this, store the signature as a file in your computer by scanning the sheet of paper, by using Mac Preview and the webcam, or by using Mac Preview and the trackpad. If scanned, the resulting file may be in any of the formats: PDF, EPS, or PNG. The PNG format allows a transparent background.
To insert the signature into a (Windows or Mac) Word document, use Insert > Photo > Picture from File.
To insert the signature into a PDF document, and the signature was stored using Mac Preview, then use Tools > Annotate > Signatures in Mac Preview.
To insert the signature from a file into a PDF document, use FormulatePro (this is installed on all properly configured office Macs) as follows: