If you can support yourself, then it takes away your parents leverage over you. Be prepared to get your own place when you turn 18, as some parents refuse to support a child who will not attend church and go on a mission.

Make sure you save some money and keep it (hide) safely away from them, as we have heard stories of parents confiscating funds in order to bring a child to heel and create a situation where the child needs them.

Sorry, better prepared than up against the wall. Some Mormons can be real controlling, I don’t know about your parents, you’ll have to make a call on that.

If you can possibly help it, never have a savings or bank account with any name on it but yours.

A bank account with your name only on it, as Mia suggests, is also great advice.

If your parents want you to have an account with your name & theirs on it, fine. Then later open your OWN separate bank account in addition. (For various reasons, people often have more than one account in a bank, so there is no problem in doing this.)

If you are still living at home when you open your private account, you may consider having a Post Office box as well, where any bank mailings would be sent.

My parents cut me off as soon as I refused to abide by "their rules" (be mormon). I was 17 at the time. I moved out and lived with friend's families while still finishing high school.
I am currently 25 and still having a hard time financially. My dad's advice is to contact my local bishop. He says he will "help with the funding" as long as I go through the bishop here.
My sister is 22 and still living at home. She doesn't have money saved up. She just finished college and my parents are sending her to Utah to live with my mormon aunt and find a job out there. She really doesn't have a choice.
They will control your decisions any way they can. Being self sufficient takes a LOT of that control away from them.

Thanks for all the great advice. I wont be moving out before 18. I love my parents and their values just not their religion. This forum has really helped me get ideas on the best way to break it to them that im not the perfect mormon son.