Newbie to GC and still working on improving my social skills using what I've learned here, but I think I can chime in here on fashion because I do get the occasional compliment on my style.
There's no secret to dressing well--dressing well is very much discussed by many, many people, to include masculine men. Furthermore, there are very prominent men's magazines based here in the US that focus mainly on fashion.
My go-to magazine is GQ, as I am a guy in my late twenties. I am also a young professional working in an office environment that calls for business-casual attire, and in my experience I have found that GQ magazine, in particular, dedicates a not insignificant portion of their style advice to dressing business-casual. I would recommend reading through their style 101 section on their website, though I can't guarantee it will fit what "look" you are going for. Furthermore, unfortunately even for me, the 101 section didn't cover absolutely everything, but it is the section I recently focused on when I recently made a new effort to update/improve my appearance. As for my personal "look", I am furthermore looking to add a bit more of an edgy/sexy vibe to it, but I predict this will be easily achieved by adding an article (such as a jacket/outerwear) or some accessories that will serve to do a bit of "peacocking" (see the GC article).
I am going to speculate that it is entirely probable that your shirt is just too tight to the point that it doesn't work for you nor does it look good, hence the heckling from the other guys. In fact, the GirlsChase article on fashion and style was the only article on the website that I can honestly say I disagreed with and subsequently disregarded more than half of the information found there -- the tiny shirt advice ranking at the top of that list! Second place: New Religion jeans or whatever was recommended in the article--they are way overpriced and have that reputation (and therefore could come off as a bit indicative of being a tryhard--buying your way towards looking good when it just comes off as you judging fashion not by personal opinion but rather by price tag "$150 jeans? People must think they look good then.") While I am trying to steer clear of very specific advice, for the fact that you may have a look that you are trying to achieve which I am most likely not into, I think I can venture into making a recommendation for jeans. Simple advice: google raw denim, and in case you don't discover it right away, the best raw denim comes from Japan, and there is a pretty interesting historical aspect of the reason why that is.
So, other guys are dissing you tiny shirts. If you find, however, that the girls can't keep their hands off of you then keep wearing them! But if not, then make the change. Adage: "Wear your clothes, do not let them wear you." You have to be confident in yourself when you wear your clothes and, most importantly, enjoy wearing them plus look forward to going out in public wearing them. It is apparent to me that, in your case, you can't enjoy wearing your clothes (and for understandable reasons), as I know I sure wouldn't if it meant that I would frequently draw criticism for my shirts fitting too small.
Reviewing my reply here, I realize I've kind of gone off track from staying focused on your question, but it's probably because I don't often have a chance to give my insight on any topic here, since I'm a novice on most topics regarding GC. But anyways, I still have one more smattering of advice.
Be flexible, and use your best judgement when applying what you read of published style advice (if you choose to follow through on my suggestion). That is in regards to giving consideration about the appropriate formality of attire for the appropriate situation/environment, as well as giving reasonable consideration to the culture and norms of your social circle. Don't dress too weird (for lack of a better term) in comparison to those who you surround yourself with in public--you do still want to have some customized and personalized style, but in my opinion women as so much more observant of such things than men, that you can achieve this goal in the eyes of women while staying under the radar with other guys. I could be way off and not in accordance with GC advice here, but I don't think it is a good thing to have other guys calling you out like in your situation, and I'd go a step further to propose that being "under the radar" with other guys would be an advantageous posture. So take fashion advice with a grain of salt, as much of it tends to lean towards turning into a dandy, which works for some personalities but not most.
Perhaps the following example will portray me as a bit of a sheep, but I would disregard that assessment anyways. My personal example: GC staunchly recommends to me that I cuff my jeans, going as far as to partially expose the socks. I don't follow that specific piece of advice, and I'll tell you why. I don't see this being done but by maybe one out of every twenty well dressed guys I see here in the major city I reside in. Cities tend to even be a bit more fashion forward, yet still this advice to cuff the jeans simply isn't catching on, so if I were to do it I would stick out like a sore thumb. Oh, and that one otherwise well-dressed guy out of every twenty looks quite obviously self-conscious, but maybe I'm projecting. But enough about the god-damned cuffs. The advice I intend to convey through this example is to be observant of the norms within your social circle or even your area of residence, and then make the call, deciding whether or not you would net a positive result by wearing such and such in such a way, or if you would net a loss due to things like criticism or garnering otherwise unwanted/excessive attention.
But there I go feeding my for verbosity. Time to sign off!
