J.S.
The best way to deal with a temper tantrum is to ignore it and to not give into what it is she wants. The minute you give in she realizes that throwing tantrums works to get what she wants. If you ignore it she'll eventually realize it doesn't work and that mom means business. Once you start doing this the tantrums will get worse before they get better but hang in there it will get better. If you are out in public, store, restraunt, etc. Pick her up and leave until she gets control and then try again. As a mom of 4 I've been there but it does get better.