For your beard to be a magnet for girls and a detail that sets you apart from the crowd, the proper grooming is number one rule.
Start by washing your face and neck with beard soap or shampoo, then comb all the hair in a downward direction in order to equalize them. This will help you see what you have to shave and trim.
Shortening neck hair is perhaps the hardest part of shaving. Imagine a curved line that goes from ear to ear and meets in the central point about an inch above the Adam’s apple. You can determine this point by placing two fingers on top of the Adam’s apple, shave anything below that point.
Growing a beard
Although growing a beard, it should be shorten. After a month or two of growth, your beard will become uneven, so use the trimmer on the longest length and gently move along the chin to equalize and shorten the hairs that stick out.
In essence, all of these rules apply to the mustache also. Comb them to equalize all the hairs, trim them with a trimmer on the standard length, and then use the shorter length to remove any hairs that stick out and cross over your lips. If you are really committed to your mustaches, use scissors to cut short hairs under his nose.