When my daughter was little and touched something dangerous/did something naughty, we said a firm no and if she continued to touch something, we'd give her a little tap on the hand. Not hard at all and certainly didn't leave a mark.
My sister in law on the other hand will not raise her voice to her darling daughter (who is the queen of tantrums) and runs riot everywhere. We were in a furniture shop once and everyone was staring at her as she was running through the furniture and ornaments. The whole family comment on what a naughty child she is. It's not her fault though, it's my sister in laws!
I don't smack my daughter and never have. We used to tap her hand.
If she's naughty now (she's 3) we tell her off, if she still doesn't listen, we raise our voice and say last chance to be good and if she's still naughty, we sit her on the naughty step. She's pretty good most of the time though. This is what works for us though.
Onlyme - I think you may have let your daughter have her own way for too long. I think filming her is a great idea as my husband did that not so long back and my daughter watches it and agrees how silly and naughty she was being at the time.
Good luck, you just have to be firm and stick (that's the most important part) to your methods.
P.S I was smacked on the bum when I was younger and I'm completely fine with it and respected my parents. They always gave a warning and I always deserved it as I'd carry on. To be honest, I think most of my friends were smacked too.