Make sure you are holding the piece of paper steady and your writing matches the guideline. Start by writing a signature on a plain, white paper and then simply holding it up to the webcam. STEP 6- Alternate way to add signs is through the Camera option. Scribbling it on a trackpad using your finger or stylus is the easiest yet quickest way to add signs. STEP 5- Now you have two options to create a Digital Signature To Sign A PDF on Mac. You need to hit the ‘Click Here’ option to begin the process. You need to click the Create Signature option to make a new one. STEP 4- Since you are signing a PDF for the first time on Mac. From the list, you need to look for the Sign icon that looks like a ‘Scrawled bit of handwriting’. You can see tools for Sketching, Drawing, Adding Shapes & more. STEP 3- As soon as you click that option, you should be displayed the set of editing features.