My 450 swallowed a peice of firewood a neighbor pushed into the road with his plow last winter. I wasn't real happy. No serious damage done but it took me 1/2 an hour to get it out with out dismantleing the blower.
Tips#1 SAFETY 1ST. THESE ARE POWERFUL MACHINES AND CAN HURT YOU BAD IF YOUR NOT CAREFUL. DO NOT PUT YOUR HANDS ANYWHERE NEAR A RUNNING SNOW BLOWER. This may seem obvious but it's easy to get lazy when your out in the cold and the wet snow/slush has clogged the chute for the upteenth time. Don't do it. Turn off both the blower AND the tractor before attempting to clear the chute. I carry a very large screwdriver or a piece of furring strip 18"-24" long to pry frozen slush out of the second stage and chute. This stuff will clog it up. That's really the blowers main weakness.
#2 Safety again, Always be aware where the chute is pointed. Just like a gun. Know where the muzzle is pointed at all times and be aware these things can throw stuff with a lot of force. My 450 under the right conditions will throw snow well over 60ft! Never blow snow in the direction of people.
#3 Always blow downwind if at all possible. Work smarter not harder.
#4 Spray them down with PAM or Wd40 inside before use. Helps keep the snow from sticking.
#5 On gravel drives raise the blower with the skids about an inch to keep from sucking up rocks.
#6 Drift cutters can be a huge help. Often the snow is deeper than the blower. Drive into it and knock it down. Back up and then go forward again to blow the snow. Some times you'll do this the entire job over and over.
#7 Don't beat up the equipment. These things work well but be patient. Moving snow is hard work for you and the tractor. Don't try to force it. The tractor will tell you the right speed if you listen to it.
#8 Dress warm. You will get covered in snow. Clearing the drive aint worth hypothermia.
#9 Make sure you are seen. Most of us do alot of this work at night. Make sure you have lights and reflectors. Reflective tape is inexpensive and makes it easy to outline the rig so peaple can Identify that thing in the headlights.
#10 Use your head, Be aware of the equipment and what is going on around you. Where people are cars ect. This is just everyday tractor sense.
#11 You will need wheel weight and tire chains.
#12 One more. Go to the dealer and get at least one change of shear pins for your specifc snowblower. 2 changes is better. If you have them you won't need them. But if you don't you will. Bolts instead of shear pins can cause serious damage if they don't snap when they are supposed to.
Enjoy the ride! Moving sbnow can be very satisfiying. Let it snow, let it snow let it snow!