Hello all, I am about to go get my second piece cut in and i rememebr last time my stylist cut it right up to the hair. However people always say leave an 8th of an inch in front of the hairline, is this the right length to leave??

anyway i wanted to ask what is the purpose of leaving this bit in front of the lace? is it to help align it, i.e. easier to draw with a pencil around the outline of the front? thanks for any help