The key techniques used in backchecking include maintaining proper positioning, reading the play, and anticipating the opponent's moves. Players need to skate hard and quickly close the gap between themselves and the attacker. They should use active sticks to disrupt passes and poke-check the puck away. It is important to stay between the opponent and the net, while also being aware of other potential threats. Communication and coordination with teammates are also essential to ensure effective backchecking and defensive coverage.