How do you motivate workers?

Im on te Basketball team, and some of the kids dint take it seriously If we do bad. I get really pissed at practice especially bcuz practice makes perfect and they don't care. I just tell them to step it up and encourage them even if they do good or bad, that's the sign of a real leader. So be a leader and lead ur team. If u see someone slaking at practice call their name and tell them what to do. That will show the coaches and teammates tht u care. Btw I'm 14