Hi, Pam. I know exactly what you mean in regard to having everything planned, and then little aspects of business transactions just keep on popping up!
What I do as far as signing agreements is that after I have emailed my client my agreement(s) and he/she has emailed me theirs, we schedule a telephone or Skype call and then go over our agreement(s). It usually doesn't take over 15 minutes, and I feel it gives both of us a chance to make any changes right then and there. It's really easy to do using Google or even making "adjustments" to the agreements and emailing back the revised documents.
Once we have both signed each other's agreements, I prefer to scan them and email them back right away. In addition, I like to do it the old fashioned way and mail originals/copies. Hey, we've got to keep our postal service in business somehow! It's worked so far for me. Did I answer your question?
Congratulations on signing your agreement with your client. That is awesome!