I usually load my forks, tooth bucket, and v-shaped "stump" bucket on the front of my trailer from the driver's side all in one pick. I then use 2 chains with binders to secure them to the trailer. Two chains prevent the attachments from twisting/spinning on the trailer during transport. I load these three attachments from the driver's side because I may only have access from one side of the truck when I am parked at the job site.
It gets a little more difficult when I bring my Brushcat with me. If I load the Brushcat on the front of the trailer, I use nylon ratchet straps to secure it so I don't scratch the paint on the attachment. I utilize nylon ratchet straps on attachments like rototillers, soil conditioner, sweepers, etc... to protect the finish of the attachment, but yet still secure it. Most of the time it is easier to leave the Brushcat attached to my SSL and load my other attachments on the front of my trailer normally.
You can never seem to have enough chains, binders, and ratchet straps. I am going to build a box for these permenantly mounted to my trailer. It is also a good idea to check your load and adjust any chains or straps a couple of miles into your trip because the load may have shifted.
I also plan on building two rectangular tube steel pockets underneath the sides of my trailer, which I can load my forks into from the side of the trailer and secure with a short chain. I may even load them from the passengers side of the trailer, so the fork headache rack acts as a secondary safety in case my load shifts.