Who: For strokes in front of the wicket, the striker will call for the run. However, when the ball goes behind the wicket or at a place where the striker cannot see the ball, its the non striker who calls and the batsman responds. For the second run, the person running towards danger, that is in most cases towards the wicket keeper should call for the run.
It is important to remember that since the striker hits the ball and he is the best person to know the angle, speed and the distance on the ball.
How: If any of the batsmen wants to refuse a run, he must do so before setting off – loud and clear. There are only 3 universal calls with clear meanings:
No: Don’t run, or stop and run back
Wait: Means go as far as you can without falling short if you were to run back. Use this if you want to check if you were able to pierce the gap in the infield.
Don’t use any other words or a combination like “wait no”, “wait on”, “stop”. Your current team mates may understand you, but if you progress to a better team, chances are you will be misunderstood. And that may cost you a career. So follow the right habits.