I have found that the most eye-appealing look to a nice gable roof is the straightness of the shingles along the drip edge. When laying shingle down in place, take a utility blade and wrap an arm underneth the shingle, near the soffit and place a straight blade at the top of the shingle along the D-edge. Then with a little muscle power, pull the blade through the asphalt shingle and cut it staight and crisp with the edging. The drip edge will guide your blade straight and will leave a professional look to the gable end of your house.
Submitted by users to WD-40 JobSite