A good defense is vital the more court you can cover, medicine the longer you can stay in a rally.
The aim is to return the shuttle that is being smash at you high into your opponents court. Although most top players prefer to defend with their backhand, sometimes you will have to use the forehand defense. It is important when this happens, you are confident to get the shuttle back.
Start with a split step when possible, step forward to meet the shuttle. The racket head moves momentarily outside the line of the shuttle. Using a relax forehand grip, supernates the forearm on the back swing. Tighten the grip on impact, hit through the shuttle and pronate to a relax forearm. Bend the legs when the shuttle approaches and straighten to power the hit.
Note the bend wrist position, as the racket head goes forward to strike the shuttle. Played it well and you forces your opponent right back.