Great question Keelan! First off, every scholarship application is different and might require you to provide specific documents or answer specific questions. However, based on my experience I would think it is important to include the following items in any scholarship application: 1) a copy of your résumé, 2) a copy of your Transcript from you current school, and 3) a personal statement.
A résumé is a document that you can use to list and describe items such as: your GPA, extracurricular activities, work experience (if you have any), interests and hobbies. This is an important document that you can use to help list your activities and any accolades you have received for the reader to have insight into your experiences and interests.
A personal statement is a brief description of the beliefs and core values that are important to you. Since your résumé is basically a list of your experiences, this personal statement can be an opportunity to go into further detail of a specific experience where you were able to live out one or more of your core values. For example, if volunteering is important to me so I could describe a specific instance where I volunteered at a Soup Kitchen and how the experience impacted me.
Lastly, as I mentioned above, every scholarship application is different, but these are a few of the key elements that I have found to be essential in any scholarship application.