You submit a plan to spend anywhere from 25,000 to 1,000,000 miles. You don't have to have firm dates etc. when you submit, but the rules require winners to actually follow through with their plans within 2 years.

You can't submit bungee jumping in China and then go visit your cousin in Fresno. (Likewise, you can't submit visiting your cousin in Fresno then go bungee jumping in China.)