I'm officially done with uhaul trailers. At 30 bucks a pop, 10 track days at year, its just not worth the price. The motorcycle trailer has been stable and useful, but I just dont have time for the additional 2 hours it takes to pick up and drop off. The check in/check out process at my uhaul is always a pain. But I might get into some novice racing this season, so I'll be tracking much more than usual. As far as what I used to do, I would just use 2" webbing, around the forks and rear foot pegs like shown in the manual. It has always worked well for me. Just enough pressure for nearly half way down the front shocks, and about an inch and a half of compression on the rear. You have to figure out a way to rig the front fork straps as close as possible to the wheel. If you move them further (laterally - X axis from riders perspective) from the bike, it can start putting stress on the plastics (no bueno) - if that makes sense. Imagine a triangle from vertical at the forks to the tie down point. The sharper (smaller) the angle at the top of the triangle - vertically from the fork to the tie down - the better (within reason, you still want some lateral support).
I used to rent u-haul motorcycle trailers too, and the time wasted comes back to haunt you. It's cheap, but it's not worth the time spent waiting after people, going there, taking it back etc. You can do the online reservation, check-in and all that, and it goes faster, but you still have to wait for everybody ahead of you, and it just takes forever for 1 person. Plus the mentioned take it home, take it back part with all the loading/unloading.
For holding the bike in place, I used to use a canyon dancer for the front wheel and the wheel was in a Baxley chock as well. The straps hooked up to the canyon dancer ends and to the now ex-rear foot pegs in the back, re purposed for hooking up the straps. I did this for 10 years or so.
However, with your own trailer I found the Pit Bull trailer restraint system (and probably there are some clones/variations of this system) is much better. It's expensive (around $300), but it lasts forever. You drill some holes, mount a base in the trailer, open, closed trailer, it doesn't matter (there are ways to not drill through the trailer floor but hook up the base anyway), and the bike hooks up to this base with some pins that connect to the rear axle.
It needs different pins for connecting to the axle for different motorcycles, but everything else stays the same. Some fit on more that 1 brand of motorcycles, for example the r1 pins also fit the bmw in my case.
That is all that is needed, it doesn't even need anything in the front, and no straps, no compression of the suspension at all. I think it works great.