Tie-down straps are not the most exciting subject in the world of motorcycling. But, good straps are important. I used cheap tie-downs once and I regretted it. That error in judgement led me to the Fat Strap trailer kit from Powertye.
There are many other less expensive straps on the market, but "you get what you pay for" applies here. I have trailered everything from scooters to heavy cruisers with these straps and have never had a complaint with them.
These are quality, heavy duty, and come with a sheep skin sleeve that prevents the nylon strap from ever touching your bike. When I tie a bike down with them, I am confident it is gonna be upright when I reach my destination.
Take a look at these pics and decide if these straps will work for you. I have the 1 1/2" strap kit, but they are available in in wider sizes and different colors. Visit the Powertye site for more details.