I have a load of off cuts of rubber roofing sheet which I use, cut into about 1" wide strips. It is V handy to have some cut shorter and thinner, this allows you to get something strapped in place before you start heaving on the bigger straps.
It's a damn good work out wrapping bows.
IMO it's good to get at least 2 layers of strapping. It will be hard to wrap too hard and squeeze out all the glue, it's much less harsh than rigid clamps and it distributes the pressure better.
Del