Sorry my last post wasn't very helpful, I needed to get to a real comuter with a keyboard.
If I can help it, I only ever cross the staps on one axle, not both. Usually the front gets crossed since that arrangement works best with the location of the tie down points my trailer and the LHD axle/panhard/drag link arrangement. I loop the strap all the way around and slide it up snug against the pumpkin so it cant move when I am drag racing in rush hour traffic.
Try to keep one of the tires on the vehicle being towed in your mirror and look at the tread when you are starting/stopping. If the truck is rolling it will be very easy to tell this way.
For longer trips or lifted vehicles, I may use axle straps AND the factory tie down loops to suck the suspension down a little. I have noticed that on lifted D1/RRC/Defenders that still have old factory radius arm/rear link chassis bushings fitted that using the axle straps alone can quickly make those bushings useless, which will lead to a nice "death wobble" or "wandering" feeling.
Also, new straps take some time to stretch a little so prepare yourself for more frequently checking on them until they "break in".