MT, there's always the plain and simple method of going for a hike with a canoe on your shoulders. I haven't done it a lot, told myself I would do it more than I actually have, been some years I've spent a couple weeks walking a mile or so a day portaging my canoe. Seems to make the "real" portages easier on the shoulders.
The other thing that worked well is I used to work as a delivery guy for a lumber yard so I tried to go the extra mile on customer service by carrying lumber to exactly where people needed it no matter how far it was because it gave me the added bonus of doing a lot of walking with heavy long stuff on my shoulders. Not exactly a canoe but every bit counts.