Final answer:
To perform a bevel-under effect, the blade is positioned behind the hair section and moved in a downward and forward motion for a polished and refined look.
Step-by-step explanation:
To perform a bevel-under effect in hair styling, the blade is positioned behind the section of the hair and moved in a downward and forward motion. This technique is commonly used when creating a layered or tapered look. The bevel-under effect adds shape and movement to the hair, giving it a more polished and refined appearance.