O.K. sidney411, I'll share but a little disclaimer first: I am not recommending or suggesting, only sharing. Thus, not responsible for damage to equipment or person.
So here is what he showed me; I've used it several times with success. Get two strong, straight poles (I usually cut a few elm trees approx. 5" dia.). They need to be long enough to extend past the back tires and beyond the front tires. Lay one pole on each side, parallel to the tractor, up against the front and back wheels on each side. Take a heavy log chain and run it under the tractor in front of the back tires to connect the two poles together. I usually just make a loop: end of chain under the first pole - under the tractor- under the second pole and back over to the first pole and connect the chain to itself. Pull the chain tight and up against the back tires - having the tractor tire tred catching the chain if possible. Low gear, tractor will climb the chain out of the hole, poles will keep the chain from sinking too far in the mud.
Some places where it was real wet, I had to repeat it a few times until I got to solid ground. I've never tried it with a 4WD, I guess you could use two chains with a 4WD, one for the front tires and one for the back.
Your milesage may vary.