A person who puts a large amount of effort into achieving a certain image, or counter-image, to the point where it is obviously contrived. Rather than achieving an image through genuine personality, the try-hard consciously attempts to fit a certain style through deliberate imitation, forced style, or scripted behavior. That is to say, he/she is trying hard to create an image..
Examples: An affluent, suburban dweller who makes great efforts to cover himself in tattoos and piercings; try-hard.
A person who wears certain items of clothing for the express intention of appearing "non-conformist", and flaunts it; try-hard.
Someone who purchases a motorcycle only to appear as a "bad-boy"; try-hard.
A person who shuns certain genres or styles of music or art simply because it does not fit his self-image, or the image he wants to portray; try-hard.