Your original question isn't clear. Are you asking us how to format a resume or are you asking what types of activities you should pursue in order to increase your chance for an appointment? Good to realize there isn't one magical combination of activities that will result in an appointment so asking others what things they did in h.s. isn't really going to tell you anything. Typically, those who got an appointment excel in academics, ECA's, athletics and have been successful in leadership positions.
As mentioned above, good to read all of the posted stickies and explore the entire USMA website which contains answers to the most commonly asked questions.
You also didn't say which year in h.s. (or college) you are. Better to do the things you enjoy, are good at and can contribute to the success of your school instead of just doing things to make a better looking resume.
