When you're little, your parents have control over pretty much everything in your life- the food you eat, the kids you play with, the activities you get signed up for, even the clothes you wear.  It's important that parents decide these things because a small child is not yet equipped with the understanding and ability to always make the best choices.  But as you grow older and more mature you're able to start making decisions for yourself- and you probably want to exercise that new right whenever you can!  At the same time, your parents have spent years making the decisions for you and it may be hard for them to start to let go.  It's during this time of change that it may seem like you are ALWAYS fighting with your parents no matter how hard you try to get along. 

Though conflicts are sure to arise, and your life may even seem filled with constant bickering, there's no reason that the new power struggles you are experiencing have to ruin your relationship.  You need to remember and recognize what's really going on when the problems come up.  Yes, in the heat of the moment it can be very difficult to think rationally, but it can mean the difference between hurt feelings and resentment and a solution that makes everyone happy. 

Because most fights will be about power and control, your parents will be looking for signs that you are mature and responsible enough to make good decisions.  Think about the message you send to them when you scream 'til you are red in the face, stomp off to your room and slam your bedroom door.  Those are the actions of a child- not a young adult and your parents will probably respond accordingly.

One of the most important things to keep in mind is that, although it may seem to you like your parents don't trust you or respect you, really, it's probably that they are just having a hard time easing up on the reigns and watching you make your own decisions- and your own mistakes.

Now imagine the difference in tone if you were to say to your parents something like "Mom, Dad I understand that you're nervous about this, but I really think I am ready to make this decision on my own."  You sound confident, calm and most importantly- mature.