Many high school students consider their summer vacation well spent if they perfect their tans or earn money flipping burgers. Identify contests you want to enter, obtain applications early and jot deadlines on a calendar. Examine the rules closely. Apply, apply, apply. Judging is subjective, so increase your odds by entering several contests.
Smaller scholarships can add up.
Develop reusable material. Recycle essays on common themes. You also can tweak it for college applications. For contests that are more focused, pick topics you can adapt for more than one contest. Maintain personal inventory lists.