In this tutorial I am making a very small vessel using a golf ball as the form. It is a good idea to start with a small project as you get a sense of the process. The first step is to lightly wet down the shape you've chosen. Then gently add a thin layer of fiber. Remember whatever colors you choose for the first layer will be the colors of the INSIDE of your vessel. This may be important when felting a large, open vessel.
When felting larger objects you will need to apply gentle friction to small areas at a time but the process is the same.