If it's like a pine or spruce, then I would use maybe 2 inches lattitude. If it's really leafy with big leaves, perhaps a little more lattitude is needed, like maybe 1/2 a foot.
It also depends on the season. Unless the pine or spruce is covered with snow, I wouldn't change the latitude. If it is covered with snow, knock the snow off.
For something like a maple in winter, I'd reduce the latitude to 3 inches......
