"Stop making that face or it will freeze that way"
"If your kitchen is dirty, your whole house is dirty!" (something that has stuck w/ me to this day!)
"It doesn't have to be new, it doesn't even have to be nice, but there is no excuse for it not being clean! Soap and water are cheap!" (again, something that has stuck with me 50+ years later!)
When we said we were bored, she'd always say "I've got something for you to do!" (a.k.a. work!) to which we would always stomp out of the room.
When we would constantly ask what was for dinner, she would always say "pig shit and hominy now go outside and play"
And as everyone else commented, we too got the there are starving kids in Africa thing... sometimes followed by "you'll eat what I fix and put on your plate or go hungry!" The fact that many people I know now with young kids will fix several different things for one meal to ensure that all the kids get something they "like" drives me crazy!