One thing I did do right: the temptation to bring a friend along to my booksigning to keep me company was enormous. However, that companionship would have taken the edge off for me. I don't think I would have been as motivated.
I've heard the argument that having multiple authors present creates more sales. I suspect that is only true if the authors already have a fan base OR if the signing receives advertisement that generates traffic. For debut writers, I think you're better off going it alone for two reasons: (1) You're more hungry when you're out there alone, and (2) You're easier to approach when you're alone. Of course, if you can do a signing with a better-known author in your genre, and if that author is generous enough to direct people to pick your book up, you could benefit from the company.
I don't know if my assumptions are correct or not. I'm looking forward to opportunities to find out.