Passing quickly gets the ball upfield and reduces the risk of giving away possession.
The sidefoot (inside of the foot) provides the greatest accuracy for passing.
But it is difficult to generate power and it is also easy for an opponent to see where you are intending to pass the ball.
For those reasons, it is best to use this skill just for short passes.
Ideally, you want to approach the ball at an angle of about 30 degrees so that you have room to swing your kicking leg through.
Get your non-kicking foot close to the side of the ball, use your arms for balance and keep your head still and eyes on the ball.
Keeping your ankle firm, bring your kicking foot through and strike the centre of the ball (to keep it on the ground) with the side of the foot.
With this type of passing you are looking to keep the ball low so that it is easy for a team-mate to control.
The weight you put on the pass is also critical.
Follow through with the kicking leg to increase power, but the weight of the pass will depend on how far away your team-mate and opposition players are.
You will become increasingly better at judging this the more you play.