Darts tuning is meant to determine a setup for you darts that fits your throw, which also mean right flights and shafts. The angel of the dart should be within 10 to 45 degrees when the darts stands in the board.
How to tune your darts? You have to use various types of flights at first. The bigger flights make a bigger angle then a slim flights, and if you use medium shaft with a slim flight the angle attend to go downwards and not up, make sure to get the angle upwards around 10 – 45 degrees. Try out different flights shape then experience the same flights with another shaft, medium, short or extra short. Also try different barrel weights.
Darts tuning needs work but you should have figured it out within a couple of days to eliminate possible variance in your throw. When you find the right flight, shafts and barrels, you will know it because your game has improved.