Best age to start disciplining children
Um.. As soon as they need disciplining? LOL that's not a very clear answer, but I feel like it's never too early to discipline APPROPRIATELY.
You have to try and put yourself in the baby/toddler's shoes. Are they really acting out or do they just not understand that what they're doing is wrong? I lean towards explaining everything first since Avery's so young I don't think she completely understands right and wrong yet. I'll say no and remove her from whatever the situation is. It can take several times for a baby to learn something so it's okay to repeat yourself over and over again. As a child get's older I wouldn't let them get away with that.
I also don't put up with tantrums at any age. Avery had her first tantrum at about 10-11months and I calmly removed her from the situation and let her calm herself down. She didn't get whatever it was she wanted but I let her play again once she was calm.