>height
You've stopped growing. If you'd like to appear taller in public, you can try inlays.
>weight
Getting Veeky Forums will do wonders for everything in your life, including the way you're perceived. As people gain weight and develop muscle, their face generally age somewhat, too. Their facial structure becomes more "coarse", or more adult. Gain weight and you will look more adult, and not like a twink. This will obviously also make you less frail.
>facial structure
Working out, gaining weight, and doing heavy androgens as well as HGH. Heavy roid use can make people look 10 years older. Jaw/chin surgery works, too.
>facial hair
Get a full five o'clock shadow, or grow a short beard. You probably can't do this given your other stats, so one option is Minoxidil (in the face) given you've read up on it properly beforehand. Roids will also affect beard growth, as well as exercise to some extent. If you can't grow a full beard, DO NOT grow it out - just keep it shaven.
>haircut
consider: buzzcut, high and tight, a non-cancerous neo-hitlerjugend, or modern quiff.
>skin tone
Get a tan, using a) the sun, b) carotenoids, or c) melanotan. Having darker skin will provide more definition to your facial structure.
>clothes
if you look like a kid, wearing a suit will make you look like a kid in a suit. but there are some obviously juvenile things you should avoid wearing, but they will most likely be mentioned in the thread. emphasizing your shoulders will appear more powerful, manly, and adult.
>voice
With practice, you can permanently lower, or raise, the tone of your speaking voice somewhat. I'd suggest that you practice this to get a more authoritative and manly voice. roids will also change this.
>et c
no piercings (espec. not in the ears). tattoos will make it appear to most people like you're probably +18, but can appear juvenile depending on depiction and location. wrist watches should be classic analogue, and no digital plastic ones. glasses might help.
CHEERS,
S