Heather, I looked back and remembered your question from last year about your strong-willed daughter. I think you are probably hoping to find the line to walk between coddling her and breaking her spirit. This is the nitty gritty of parenting - raising a responsible, functioning adult who can live a "normal" life in the big world. Every parent is on this journey with you!
I definitely raise an eyebrow, as the others have said, at the phrase "walking on eggshells". Your child should NOT have that kind of power in your home. If you would be horrified at your child if she were defiant to another adult, how much more should you be horrified to see her behaving that way to her own parents???
My older daughters are 8 1/2 and 6 1/2, and I can calmly discipline a lot of things, but if they are sassy, rolling their eyes/huffing, or being outright defiant, they get immediately sent to their rooms because I will not tolerate their egos trying to show me how superior they think they are! And they have no idea how much there is to learn, so there's no point arguing with them and losing control, because they have no capacity of grasping how small they are in the scope of knowledge and experience in the world. So they lose my attention and presence until they are ready to be respectful.
I understand the power of praise for actual achievements, but do not recognize the value in praising a 7 year old for getting herself dressed in the morning. Good grief, my 3 year old does that! Praise has it's place, as does discipline. Once you find the method of discipline that seems to be most effective for your daughter (it seems tantrum-throwers in general respond to lack of attention from a parent) then you and your husband need to sit down and lay out the ground rules at a non-confrontational time. "Susie, we are responsible for making you into a really great adult. We're trying to teach you what you need to know so that you can have lots of friends and a good job and be a happy person . . . you need to respect us and realize that we're in charge, not you. If you disrespect us or are defiant (give concrete examples of what that means) then you will be disciplined (give actual consequence). We are going to be firm with this, and no matter how big a tantrum you throw, it's not going to change our minds . . ." Then you have the BIG job of carrying out what you just promised.
I think these books might be helpful for you - The New Strong-Willed Child, and Dare to Discipline. Blessings on your journey!!
http://www.amazon.com/s/ref=nb_sb_ss_i_1_35/180-###-###-#...