How to cut a short layered haircut with thinned out tips:
Begin at the nape of the neck and graduate the hair. Cut the hair at the back of the head right above the separation line. Comb the hair on the sides back towards the nearest already cut strand behind the ear.
This serves as reference point. This creates a concave length increase and puts the emphasis on the front part of the head. Cut the bangs in a straight line.