Talk to them. Get to know their story. Most people just want to be heard, and being a listening ear could put in you position to help steer someone down a healthy path.
Foster the good in people. Pay attention to the positive things they are aspiring to achieve. Let them know they are meant for and capable of success.
Help people to think beyond limited social norms to see the world differently, and always allow yourself to be enlightened by others whose knowledge and wisdom may be greater than your own.