Should You Say "Goodbye" To Your Tree Before Winter?

There's an old saying that goes, "if you don't take the tree down, it will take down itself." As winter approaches, this saying becomes very true. If there are trees on your land that are not in good shape, this could be your last chance to remove them before the upcoming snow, ice, and cold temperatures do it for you. But how do you identify a tree that's ready to be felled?