How to comb hair correctly when cutting hair.
Take a section, you want to get into the root area and keep the tension the same throughout. Try to avoid this, try to avoid messy, sectioned hair. When you take a section, make sure there are no knots at all in any of the lengths. Use the thin end of the comb for tighter tension and the wider end of the comb for slightly lighter tension. Comb down evenly throughout the ends keeping exactly the same tension throughout. So to recap: keep the tension very tight and very clean.