Choose a ladder that you can lean against the wall at a 60-degree angle or less that will extend 2 to 3 feet above the edge of the roof. Drill holes and insert S-hooks about 3 feet from the top of the ladder.
Hook each S-hook onto a bungee cord. Secure the end of the bungee to a sturdy part of the soffit or an eye-hook drilled into wood under the soffit. Position pairs of bungee anchors at 8- to 10-foot intervals in areas where you will need a ladder.
Secure the bottom of the ladder with cement blocks or other heavy weights and have a partner hold the ladder to prevent it from slipping.
Remove as much snow from the eaves -- the part of the roof that hangs over the side of the house -- and other lower parts of the roof with a roof rake. Roof rakes with extensions can reach over 60 feet.
Draw snow down in lines on either side of your position as you move around the house. Cut back any drifts or unusually deep sections of snow with a snow cutter or razor, a wire that slices through snow to loosen it so it slides down the roof. Once the deepest drifts are cut back, move any remaining snow off the eaves onto the ground.
Attach an extension to the roof rake and work back around the peak with the roof rake, again pulling snow down beside rather than onto your position then clearing the eaves afterward. Clean out valleys around dormers, chimneys and intersecting roof lines.
Clear the snow around the margin of the roof where beams meet rafters with a flat plastic snow shovel to make a path.
Rake snow from the interior of the roof onto the parapet path and shovel it off the path over the sides of the roof.
Sweep paths to the downspout clear with a broom and ensure that the bases of downspouts are clear. Flat roofs actually slant a bit to allow for drainage.