Write it down, your kids will like reading about themselves later. (and as teenagers you can embarass them in front of their girlfriends with the things you have actually had to say to them.) I have been asked more than once to start a blog and post the things I end up saying to my children, things I never imagined I would ever say to another human being.
My top 5 are
Don't color your penis blue.
Stop licking the trash can at Great America!
Don't hit your brother with that frying pan!
Don't bite the dog!!!!!
Don't lick the floor!
Everyday brings something new that I never thought I would have to do or say. Never say never, karma will make me eat those words every time! You know when I was young and without kids I said I would never let my children sleep with me, I would never drive a mini van, and I would never have more than two kids. I have eaten all of those nevers and done them all. The lessons learned are these, I can't control anyone, especially my children, life will throw everything it has at you to see if you fall, if it doesn't kill you it will make you stronger, and never say never.