I updated my 4s to iOS6. Then I cleaned everything out that I didn't want. Pics, apps, messages, emails, ect... I then made sure I had a new iCloud back up.
Then on the iP5, I restored from my recent iCloud back up. Everything came over just as I left it on the 4s. All I had to do from there was enter all me passwords, and sync whatever music I had in iTunes to the 5.
After this was complete, I went to Settings/General/Erase All Content and Settings on the 4s.