I use chains. Usually G70 DOT vehicle transport chain. However, i do usually keep plenty of the 10k 27-30' cargo straps in the trailer basket. I use these to strap down cargo. I have cut some, and burned the end with a torch to keep from fraying, which often needs to be done to the long ones as well, as the factory burn doesn't last too long. if you have a chain rail on your trailer you should be buying the type with a flat hook, and they should be doubled back over themselves. If you have D-rings, the style with the round wire hooks will work, although they should be the flat steel snap style hooks like shown earlier, so they cant fall off should a failure of some sort occur.
If you leave the straps long, the best way to take care of the extra is to fold the extra back into the ratchet and then tighten it down. This cuts the length in half. Then fold it over itself in lengths about 12-20" long (depending on the length of "extra". When you've folded it over itself about 4-5 times, slip half of it under the handle and click it into the closed and locked position. The tension of the ratchet will hold the extra in place, and if it were to come loose, its only half as long, so its not flying all over nearly as bad.
probably the most important thing is to get a hook that matches your trailer, and a hook that matches the tow rig, or the axle strap. You may be best off to buy two flat hook style and two round hook style and use a flat hook ratchet with a round hook strap, and vise versa for the opposite end. This will give you a flat hook for the trailer end and a round hook to fit into the axle strap on the other.