I have a tow strap kit from Summit. I think it was around $150, and looked similar to a Mac's kit I was researching. Whatever straps you get, I would make sure they clip on (a spring loaded gate so they can't fall off if they become loose)
I attach to the axles using the axle wrap straps, and the other end goes to the corner of the trailer with some tow rings I welded on.
I personally don't cross straps, and also wouldn't attach to a bumper since the jeep does bounce and suspension cycles while trailering.