I always seem to have an issue with trailer tires and mower tires. Usually when we order from the warehouse, we always seem to get the pieces of sh!t that are on the bottom of the stack. We call them pancakes. We have a ranger tire machine with the optional bead-blaster attachment, which doesn't usually work on these. Either only sometimes works, but I leave that to my dad. He's old-school, and seems well versed in the "skill." I'll NEVER do this, and I always walk far away from the tire when he's doing this.
What I HAVE found to work GREAT, is to get a tube that is close in size to the tire. Put the tube in the tire, blow it up so it blows the sidewalls of the tire out wide. If it's summer, take it outside and put it in the sun for a half day or so. If it's winter, get a heater and put it in front of the heater for a day. Remove it from the heat for an hour so it cools in place, then be very careful when you put it on so you don't compress the sidewalls again.
I understand that my inner-tube trick won't work for some due to time constraints. However, I find that this is about the only thing that works at least 99% of the time. I never have good luck with the ratchet strap trick, because the actual ratchet ALWAYS only digs into one part of the tire instead of compressing the tire all the way around.