I don't think hitting a child is a solution at all.. Idk much about childcare though.. But I guess being firm at what you allow, not going back on what you previously said is a good idea.. To give rules.. And I think we often don't talk with the children enough. Explain things to them. Why things are wrong to do. Children can usually understand much more than we give them credit for.
I remember my parents sat me down in the hallway to think about things for a while, calm down. And when I wasn't angry anymore, I could open the door again. They never locked the door, so it was my choice to come back in when I felt like it. Then they talked about what had happened to me. To be in the hallway was punishment enough for me, since the hallway was a boring place to be, and lonely too.. Idk.. I think talking to the child is the most important thing.. Explaining when the child has calmed down again..
"A journey of a thousand miles begins with just one step." - Lao Tsu -
"I get up. I walk. I fall down. Meanwhile, I keep dancing." - Hillel -