Choose a subject for your featurette. Narrow the subject down to one aspect of the subject. For example, if you want to make a featurette on cooking, you should use one recipe to perform.
Write down on paper different ideas of things you wish to incorporate in your featurette. Using the cooking example, you can include methods for filming the cooking in a shortened period, tips for the viewer and what kind of props you will need.
Write your script using the writing program on your computer. Stick to some common guidelines to gauge the length of your featurette. If you use a 12-point font and Courier font, centered text, each page of your script equals about one minute of film time. The featurette will lengthen if you have extended periods of shooting without dialog.
Edit your script and print the final draft. Make preparations for a camera and cast as well as a set to shoot your featurette. Make sure you have editing software and a way to transfer the footage to a computer with the editing software.