There are as many ways to tie something down as there are opinions about what color tractor to buy, I imagine.
Here is my view: 4 tie down points is preferred. Ideally, each corner should be tied, going to the bed of the trailer and slightly outboard. If O is the tractor:
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O
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I don't like "X" pattern chains, where the left side of the tractor is fastened to the right side of the trailer. It allows the load to flip sideways without any mechanical failure. The way I showed does not. That is, in my arrangement, in order for the load to flip, something has to break.
I usually use a combination of ratchet straps and chain. I like this combination because it's easiest to work for me. I put chains on the back, then use straps up front to tension everything. For heavier stuff I have chain binders, both over-center and the screw-type ratchet design.
The majority of what I transport is under 3000lbs, but I use 3/8" transport chain and 10,000lb rated ratchet straps. Nothing has ever come off, or anything like even loose. However, I always have one more safety chain, at the front and rear, just put on hand-tight, then tensioned with a motorcycle tie down strap sideways.
I wrap a bungee cord or ziptie around the chain hooks to make sure they don't come off, even if their tensioning is reduced.
Make sure the tie down spots in your trailer are STRONG. The B7100 is only something like 1100lbs bare, but if you have a loader or any other implements, it's easy to come close to doubling up that weight, especially if ballasted.
You'd likely be fine with 4 of the heavier duty 1.5 inch ratchet tie downs as illustrated above, since it's relatively light, but it's hard sometimes to find a straight shot to attach solidly to the tractor and not run the strap over a corner or put a sideways load on the tiedown hook. If you have a loader the same is sometimes true up front; I've used chains front and rear there, or a piece of chain from the tractor to the ratchet strap.
Congratulations on your purchase, good luck, and welcome to orangetractortalks! I'm excited to see pictures.