When it comes to signing a document, we often use the phrase "sign on the dotted line." However, there are several alternative phrases and idiomatic expressions that can be used instead. For example, you might say, "put your John Hancock on this," which refers to the signature of John Hancock, one of the signatories of the Declaration of Independence. Other options include "sign here," "endorse this," "affix your signature," and "put your pen to paper." No matter which phrase you use, the important thing is to make sure you understand what you're signing and that you're comfortable with it.