pressure you used to cut the hair. Trim up to your hair line to do this. The hair line is where your hair is full not just where you have little strans of hair sticking out. Your hair line should look even all the way around if this is done correctly. I like to think of it as a crisp look. Very defined lines around your hair line. Do not be afraid to go into your hair line slightly to even oout your overall lining. This is normal. To get the best chance of an even lining start from the sides of your head and work your way to the front of the head so the two sides meet. Look at photos for visual example.