When using an extension ladder in cleaning gutters or going on the roof of the house, etc., your weight on the ladder can damage, crush, or even tear off your gutters when you put the ladder up against the gutters before climbing.
To prevent damage by a ladder, get a delivery type plastic milk crate. Place it on the ground, open side down. Extend the ladder at least 3 rungs above the crate. Use wire, string, or bungy cord to secure the crate to the ladder, around the middle of the rung itself.
Slowly raise the ladder, with crate attached, to the roof just above the gutter. The crate will sit directly on the roof, keeping the ladder off the gutter, preventing contact, therefore preventing crushing or bending the gutter! The crate will sit flat on the roof, no matter what pitch, making the ladder more stable also.