By far, a trailer is the easiest way to move your pony around on your property, which is especially useful if you own a large plot of land. When you trailer your pony, you can keep him tacked up and ready to go.
To start you will need to own or have access to a horse trailer and something with which you can pull the trailer (e.g. truck, SUV).
Once you have your trailer parked with it's ramp down, introduce your pony to the trailer by walking him around it once or twice before slowly walking him up the ramp. When walking up the ramp, you do not want to be overly forceful with the pony, but also you do not allow the pony to just stop on the ramp. You may need the aid of a crop/whip to encourage the pony to keep moving.
It's probably a good idea not have the pony's arms restrained behind his back while in the trailer. This goes double if you plan on tying your pony in the trailer. Regardless, I would recommend having someone (e.g. groom) remain in the trailer with the pony/ponies for safety.
If you choose to tie your pony in the trailer, use a panic snap when possible. Also give the pony enough slack in the rope to be able to move a little bit.
With your pony now tied in the trailer (hopefully with a groom present in case of emergency) close the divider if trailer has one to keep the ponies isolated, close the and secure the doors and ramp, and drive off with your pony securely in tow. Just try not to make too bumpy a ride.