I've a few tricks that add about 5cm of illusion to my actual height. Most people think I'm a solid 5'9" (176 at least) and it's what I tell others.
Clothes & Fashion: Streamline your appearance in a vertical fashion. Avoid horizontal lines, such as cuffs around your shoes or color breaks, and avoid any large patterns (which by comparison will make you appear small). Don't wear baggy shirts or jackets as those too make you look smaller in comparison (well fitted is good). Any kind of color scheme that "breaks" your body's vertical flow (like abruptly different colored pants and shirt) will make you appear smaller - so you want to match the tones (like dark with dark, warm with warm, etc.). As a guy with a short neck and big shoulders, I avoid shirts or jackets that make me look too "boxy", so I always have a loose collar or low-cut collar - showing some neck gives the impression you're taller since showing neck is something usually seen in taller people when they dress normally. With pants in particular, can't go wrong with black. It gives a slimming impression + it should be long enough to fall nicely onto your shoes (which makes your legs look longer).
Other: The haaaair style is key. Shorter on sides with a little more on top with it either spiked or just standing up gives a great illusion + actual height. Something like this is great (and it entices women to run their hands through it as bonus)
http://www.menshairstyletrends.com/wp-content/uploads/2013/03/Spiked-Mens-Hair-2013.jpg?80deccAnd the fabled inserts. I got a .5" insert. Why only .5"? Because I won't feel bad with that much, it's still comfortable, and I'm not totally terrified about taking my shoes off in public. My pants are also long enough (as said above, they fall nicely onto my shoes) so I can even secretly stand on my tippy toes a bit if ever needed. Of course, go with whatever insert you like, but I think it's the best bump without hurting yourself or causing worry.
Lastly, exerciiiiise and posture! Being lean, at any height, will make you appear taller as opposed to a dumpling build. One of my fav exercises for posture is lying flat on my stomach and crunching my lower back by bringing my head up with my hands on my head. Stretches of any kind will help too. Sometimes I sleep without a pillow, flat on my back, and that helps with spinal alignment.
Anyway, that's all I got for tricks & tips about appearing taller. I've been a 5'7" dude passing off as 5'9" forever pretty much. If you got some other tips, pls share!