How to unshrink clothes after they've been washed & dried?

I need help, some of my clothes have shrunk! I'm not talking like kiddie size but I can tell a difference...and no I haven't changed size myself. But my mom just got a new washer & dryer so I'm not used to the settings. So after the fact that they shrank, how can I unshrink them? Like can I wash them, then while they are damp, stretch them out? Will that work?