I have some strong preferences but since every portage is different each has to be adapted to.
#1 I do not unload the canoe unless high wind or terrain forces the issue. I would rather tie it securely out of the way and carry from there. I wet foot so thigh deep water is OK.
#2 I never like to carry the canoe first. I have rammed into too many obstacles that were above my line of sight. Not to mention veering onto the side path to see the rapids or where all the moose have been heading off to a good bog.
#3 I wear my life jacket across on the first carry and that pack's straps are adjusted to fit. Life jacket and hat are left at the end of the portage. My fanny pack with GPS,energy bar, compass and batteries stays with me unless there is no risk on the portage.
# The canoe comes last along with a light pack and my cheap but rugged back-up single blade paddle that is used as a walking stick. On really rough portages I will use this for a walking stick on each carry. I can't count the times the paddle has prevented big troubles.