Summarize the following:
Be on your toes and ready to return the shuttle with a smash at any instant. You never know when a smash-worthy shot will present itself. When the shuttle is hit to your end of the court, get underneath and behind it as quickly as possible.  The sooner you reach the spot where the shuttle appears to be incoming, the higher it will be and the more time you’ll have to set up a killer smash. You may hear serious badminton players call this kind of maneuver “injection of pace.” All this means is that you add a boost of speed so you have more time to react. If the shuttle comes in hot, you might not have a lot of time to react. In ideal conditions, both of your feet will be pointing to the side of the court. Your feet should be about shoulder width apart, your knees slightly bent, and your eyes tracking the ball. Balance is more important at this point than winding up for your smash. If you’re not well-balanced, it’ll negatively impact your smash. Hold your racket upright and as far back as possible while still being comfortable. The arm of your non-racket hand should be bent at the elbow and the hand should be at about chin level.  The fingers of your non-racket hand can be positioned however you like. Curling your fingers into a fist is most popular, but you can leave them spread out, too. As you prepare to strike, imagine the angle the shuttle will travel. It should be as steep downward as possible while still making it over the net. Raising your non-racket hand will act as a counterbalance for your racket hand, providing greater stability for your smash. Aim to connect with the shuttle at the highest point possible. Inhale deeply before you swing and stretch out your non-racket arm so it's roughly shoulder level. Swing with your full racket-arm and exhale as you do so. As you swing, your racket foot should shuffle forward.  Power is important at this point, but even more important is hitting the shuttle with the center of the racket. When you feel the racket come in contact with the shuttle, snap your wrist downward. This will add power and steepness to the stroke.  You can increase the power of your smash by contracting your abs at the same time you swing at the shuttle. An overhead smash will be much more difficult for your opponent(s) to return. But in the event they manage to get it back over the net, you’ll need to be ready to send it right back.

Summary:
Approach the shuttlecock with a forehand grip. Assume a surefooted stance. Raise your arms and prepare to strike. Strike the shuttlecock. Follow through with your swing and recover for the next rally.