My girls didn't really require discipline but they still had thier days.
When they had 'thier' days, I would have them get on thier knees and have them raise thier hands well over thier head and put them on the wall.
It was very uncomfortable for them, and therefore they didn't like to be in that postion for very long.
This was the discipline that worked well for them.

Now...they'r nine. I still use that or it's isolation time.
MY girls are the type to need 'sisterly' contact. They're to be in there room with the door closed and no contact with anybody whatsoever. First few minutes are fine...and then they start getting desperate for some human contact. I found this also to be a good form of discipline without causing pain.

These things worked well for me....but every child is different so you have to work with what suits you the best.