First thing, try not to make your class a monotone speech. Try to make it a little interactive.

But about characteristics... well, maybe to be careful, consider your students opinions, don't be so harsh but also don't be so sweet. Also be gentle, with a fair load of homework. In your classes, make your students participate with some questions, opinions about situations in history, and maybe sometimes recreate the situations. But yeah, don't try to be friends with them, they'll become lazy if you do.

Well, to tell you the truth, that were the characteristics of my favorite teacher. So yeah.