There is no proper way to do this. So, creativity is the way. In view of this let me list a few ideas.
First, you might want to compare your favorite athlete or person to another great historical figure. For example, Plutarch the great ancient biographer did this to great effect. So, if you like someone like president Obama, you might want to compare him to Martin Luther King Jr. or Abraham Lincoln. Comparisons can be extremely powerful and creative.
Second, you might want to pick one aspect of the person you are writing about and expand it and look at it from various perspectives. This can be fruitful as well, especially if this something is not well known at all.
Third, you might want to be more creative a write a poem or song that describes your favorite person. By doing this, you can introduce myths and other creative forms.