The brainstorming you do for the long essay may help you come up with ideas you like for the shorter ones as well.Also consider whether some of the prompts are similar enough that you could submit the same essay to multiple schools.
Writing good college essays involves a lot of work: you need dozens of hours to get just one personal statement properly polished, and that's before you even start to consider any supplemental essays.
Next, you'll determine how to create an interesting essay that shows off your unique perspective and write multiple drafts in order to hone your structure and language.
Once your writing is as effective and engaging as possible, you'll do a final sweep to make sure everything is correct.
As I touched on above, each college has its own essay requirements, so you'll need to go through and determine what exactly you need to submit for each school.
This process is simple if you're only using the Common App, since you can easily view the requirements for each school under the "My Colleges" tab.