Some of the scarfs I made using granny-squares. Beware: once you begin, you won't stop! And all your friends and parents will want one! XD
All you have to do is make 12 granny-squares of 6 rounds, and then joind them! The number of rounds determines the scarf width, the number of squares determines the scarf lenght, so choose them according to the way you usually wear scarf. With 12 squares of 6 rounds you will have a scarf long enough to wing your neck 2 times, and fall down, and I like it that way.