The hair should be clean and damp while it is being cut. Comb all of the tangles out, and apply leave in conditioner if needed.
The layers on each side should be the same length, and to help do this, it is important to divide each side into symmetrical sections.
When you cut or trim hair, you will angle the scissors up and at a 45 degree angle, and use the tip of the scissors to cut small pieces at a time.
Take out the clip from the top front section. Make sure the hair is still damp and completely combed out. Lift the hair at a 90 degree angle
Next, take out the clip from the left section of hair. Brush through the hair, and pull it up toward the top section. Allow some of the hair to fall away.
Next, take out the clip from the right section of hair. Brush through the hair, and run your fingers through the section at a 90 degree angle from the head.
When you are finished with each section, check the length of the layers. Line them up on both sides to see if they are symmetrical.
Use a round brush as you blow dry to bring out the layers. Twist the brush inward as it dries to bring the shorter layers in with the longer layers.
How to Girl's Trimming Hair At Home