The high serve sends the shuttle very high, so that it falls almost straight down and lands at the back of the service court. The purpose of this serve is to limit your opponent’s ability to play an attacking shot.
The high serve is mainly used in singles. At the professional level, it’s used frequently in women’s singles, rarely in men’s singles, and never in doubles.
A good high serve falls almost vertically near the back line, so your opponent will not be able to intercept the shuttle early and is forced to play from the back of the court.
As the shuttle falls vertically, they will have to be careful not to hit the feathers and lose control of the shot. A smash is particularly susceptible to this.
Always use a forehand for this serve. Using a backhand is not effective.
Stand a short distance behind the service line, close to the middle line. Use a relaxed side-on stance, with your non-racket foot forward and your weight over your back foot. Use a relaxed basic grip, and keep the grip long.
Hold the racket high, near shoulder level, and fairly close to the body. Hold the shuttle high. Bring the racket head backwards and downwards in an arcing movement. Drop the shuttle out in front so you can hit at full relaxed reach.
As you hit, transfer your weight from the back foot to the front. Hit upwards through the shuttle, allowing the racket to carry on moving, over your shoulder.
Get plenty of shuttles and, ideally, a stand.
At first, don’t worry about where the serve lands on the court. Just get used to hitting the shuttle very high.
Once you have a consistently high serve, concentrate on getting the shuttle to land in the back tramlines.