Sign Document First Before Sending To Another Signatory

Hi guys, I have a contract that I want to "sign" first before sending to my clients for them to sign. I tried adding 2 Participants but this just resulted in the contract being emailed to me, then to my client. I want to actually have my signature sort of pre-populated into the contract before it gets sent to her. How do I do this? I experimented with the "pre-fill" function but for the life of me I could not get it to work. I don't  know what I was doing wrong. (I tried to select Prefill from the dropdown instead of Participant 1 or 2 but this didn't enable me to add any fields to the form.)

Thanks in advance for your help.