Driveline, flat as possible tow bar, safety chains attached to frame of 40 to frame of tow rig (don't tie the steering wheel down), lots of time for stopping, and take your time up/down hills (use your tranny,not your brakes), and don't get into a situation where you have to back up. If you do, disconnect.
I towed my CJ all over the place. 152 to Gilroy for Holister Hills and going over the pass was always a major ordeal. I would drop it into second and go about 20 MPH over the steep stuff. The truck could have taken a lot more, but with a truck lane, I took it slow to keep the tranny and engine at a good temp and it also allowed lots of time for emergency issues if they came up. Leave at least twice the normal legal length between you and the car in front of you.
The last time I towed it was all the way to Portland. I took it slow and easy over Mount Shasta and it was a very good drive.