Start throwing things back. They won't be happy once they learn that Mommy has a wicked arm and fierce aim. About the 20th time they get beaned in the melon with a Lego, they won't find throwing things as fun anymore.
Screaming
Tell them that the screaming makes the voices in your head come out. Start whispering everything you say in a super creepy voice. Say things like, "Mommy likey makey cookie. Cookies are evil. Do you likey cookies?" They will most likely be so freaked out by "evil Mommy" that they will be too afraid to scream.
Throwing Tantrums
Become a drama queen. Dropped a dish? Roll around on the floor flailing your arms and crying. Get the cable bill? Run around the house screaming, "NO! Why me! It's not fair!" Run out of toothpaste? Throw the tube down, stomp on it and scream at the top of your lungs. Chances are, your kids will be so embarrassed by your behavior that they will shape up just so they don't look like they are related to you.
Not Sharing
Stop sharing your stuff, too. Sorry, no Dora. The TV is MOMMY'S! Oh, you have to go to the bathroom? Too bad. The potty is MINE! Thirsty? NO! This is MY MILK!
Refusing to go to Bed
Let 'em stay up all night. Just tell them mommy is off duty at 9 p.m. and that they have to fend for themselves after that. Chances are, they will get bored once their slave is no longer there to serve them and fall asleep on the couch within 15 minutes of watching Bubble Guppies.
Biting/Hitting
Tell them that every time they bite/hit, God punches a puppy. No kid wants to see God punch a puppy.
Lying
Start making everything you say a lie. Make the lies really weird and confusing to throw them off guard.
Kid: What time is dinner?
Mom: We already ate. You missed it.
Kid: But it's only 2 p.m.
Mom: I know, you are REALLY late.
Kid: So when is breakfast?
Mom: Next Tuesday.
Kid: But it is only Thursday.
Mom: Yes. You better be sure you aren't late again.
Kid: But I am hungry now.
Mom: Well I guess you should have been there for dinner.