Seems like there is really no "best way" to lift them! Keep the input coming...
I worked under mine on and off for 8 months on an asymmetrical lift. I put the fronts as far forward on the radius arms as possible, and used two cut 2x4 squares under the rear frame just forward of the front leaf spring mounts. I know what guys are saying about being careful, but I guess I'm just naturally paranoid about things like that in general, so I'm a bit ADD about checking it over and again. The two by fours balance the truck a bit, so I think it was safe, and I have a pretty high standard for that. Had my boys under it too, and that gave me a nice opportunity to talk about safety over and again within the shop environment.
Now I will say that when I dropped the front axle, I had to improvise by using the forward arms under the frame near the front body mounts. That was a nice way to lift the front high with the rear wheels still on the ground, still providing lots of room to maneuver the axle out of the way, but I was never really comfortable with that setup, as the angle made me nervous about slipping. I blocked the rears, but it would not take much movement on the slick shop concrete to slip off the forward lift arms.
My advice is simply this: take your time, and lift it slow. If you don't feel comfortable, there's a reason, so just drop it back down and start over. Broncos can be replaced, but you and your family/friends cannot.
Jeff