Word choice can increase .

theme
persuasiveness
fictional stories

Persuasiveness

Explanation:

Persuasiveness is the only one that can be "increased"

The first step to write an autobiographical piece is to start with a decision about the purpose of your piece.

Explanation:

To set the purpose of the writing project you have to ask yourself some basic questions, as What do you want to accomplish with your autobiographical essay?, Why do you want o tell this story? What do you want to tell the readers with your story? After answering these questions you can start writing with a define direction that will make the thing flow easily.