Use parentheses for additional explanation. For example: "When we finally reached Grandfather Mountain (the site of the Mile High Swinging Bridge), we were excited to get started on our hike." These are referred to as parenthetical statements and provide the reader with information that is not included in the rest of the sentence. Additionally they provide data or statistics, as in "The Mile High Swinging Bridge (5,280 feet above sea level) is considered the highlight of Grandfather Mountain."
Add wit to a statement by inserting asides in parentheses. Asides are a technique used to communicate with the reader from the writer's or narrator's perspective. It may also be interpreted by the reader as an unspoken thought. For example: "I put a brave face on for my boyfriend (still shaking in my shoes) when we headed over the bridge and told myself to not look down." When using an aside, do not put a comma after the parenthesis.
Use paired parentheses around the numeral or letter used before listed items. For example: "When I was preparing to cross the bridge, I (1) took a deep breath, (2) gave myself a pep talk, (3) made sure my shoes were tied." When creating a list, place the comma after the item listed and not after the parenthesis.