In a healthy friendship, you should not be afraid of losing a friend because you say "no." Good friends should respect your right to say no and not give you a hard time. You should show your friends the same respect when they say no to you.
If you and your friend fight about something, it does not mean that you have an unhealthy relationship. You will not always agree with what your friend has to say. But you should always respect one another's ideas. As long as you and your friend listen to what the other has to say, you should be able to work through a fight.
The relationships you have will help you learn a lot about yourself. You will learn about the kind of friends you want to have and the kind of friend you want to be.
7 ways to know if your friends really care about you
Original Source: http://www.girlshealth.gov/relationships/friendships/index.cfm (this page is no longer available, however)
If you do find yourself in a fight with a friend, ask your friend what he/she thinks should be done to rectify the situation. This gives you a good idea of where the other person stands and how he/she feels. Think to yourself about their needs and whether or not what they want to see done or said is something that fits with your own beliefs and values. If what they want isn't a big deal, make it happen. Good relationships are hard to find. It is important to do whatever you can to make a relationship with a friend work. If what they want is beyond what you think is right, fair, or appropriate, then you have to express that in a way that is honest, but gentle.
Negotiate if necessary to arrive at a solution that works for both of you.
There will be times when you can't arrive at a compromise. If that is the case, then you have to be willing to let the relationship go - for a time or perhaps forever.
Above all else, don't sacrifice your beliefs and values to fit in with someone else's needs or ideals of what a friend should be like. You know what's right and you have to live in a way that reflects that.