Learn to use a chainsaw without dulling it. Being able to sharpen it is good, but nearly as valuable as being able to keep it sharp. I find that bending my knees over the years not only helps keep the tip out of the dirt, but relieves back stress. My dad taught me this when I was twelve, and I've yet to find a guy that can keep the chain out of the rocks and dirt. Sure, they look great when the saw is sharp at first, then they get a little tired, nick some dirt, it starts taking longer, I get agitated waiting for them to finish so they can help me with something else. Plus they always leave stubs when cutting brush for the chipper, they always cut 16 to 18 inches when I tell them one foot or two foot. I could rant a while, but take it to heart. And if you do dull the saw, tell somebody. Oh yeah, safety first.