In terms of spooling, synthetic will not make a difference.

Yes, most definitely! Synthetic line can otherwise be seriously damaged.

I use the concrete base of a light pole at the school parking lot, since no suitable trees are nearby. I have the driver apply either the parking or foot brake until there is sufficient drag while I spool. There should be enough drag to make the winch work hard, with the front suspension compressing slightly.

 

All answers are very helpful, thanks!

 

I just re-spooled my synthetic line. Hooked to a tree and gave the parking brake a couple of clicks. I was by my self, so I had to keep stopping to turn the steering wheel back and forth, but it worked fine. Then I got distracted putting the winch cover back on and hit the trail for a couple hours = leaving my tree strap laying at the base of the tree. Luckily, it was still there when I went back. Nobody else around on a weekday afternoon...

 

I hook my winch to my rhino and throw her in N with low pressure in the tires. Seems to work out well.

 

Important you get everything back in place with little pressure. You don't want the spool loose or messy.