S.P.
Hi there, my daughter is going to be 3 on the 25th and I know exactly what you're going through! On the one hand I know her being so independent and strong-willed is good and will be really beneficial later in life, but I also miss having my little infant that was always happy and would do whatever I wanted!!!!! I haven't yet found any sort of discipline or punishment that actually works with my daughter, but there are 2 tricks that seem to help. The first is to just ignore her until she calms down and then talk to her; the second is if it's one parent she's acting out with, the other one will come in and either change the subject or try a different approach, and usually that is enough of a distraction for the tantrum to stop. Good luck!! - S.