Body size and modeling. How does body size influence the quality of one’s life? or Influence of music on the health condition. Does music really have a therapeutic effect? there's a couple suggestions but also do something that you're into and research it
The most important characteristic is determining your audience.
In order to have the correct tone, you must know your audience. Is your audience a wealthy businessman? Then you need an intellectual, logical, and formal tone. Is the audience a friend? Then an informal tone is fine.
It depends on what you want to do in life and as for your carrier
