Most Helpful Guy
Yeah I'm kinda like you too. Plus when you work out your shoulders get broader and waist keeps toning :P
I hope I don't run into that when I'm older.
Well you should google 'slim fit' clothes and you will get several results from brands in your locality.
Levis and abercrombie and fitch are the best when it comes to casual slim fits.
Plaid shirts from these brands in specific are usually longer in length than usual clothes made for shorter fatter on the waist genre of people. Plus they embrace the shape of your body (which is V-like in most slim person cases and not flat towards the bottom), without looking like small baby clothes that fit too uncomfortably.
There are other clothes that are small in size (usually tee shirts and sweaters in cases of men) which stretch. Now these are supposed to fit, and they don't let loose on the bottom either. Plus, since its stretchable material not only is it perfect fit, it looks good too unlike loose dress shirts and all.
I also like jackets, because they cover everything up. I usually tuck in my shirts in trousers, wear a nice belt, and then wear a trench coat or a simple long coat on top. It gives you a perfect shape on the lower body and you don't have to care about fittings.
In dress clothes, yours MUST fit no matter what size, weight or proportion you are. So do keep buying quality brands and keep having them altered because that's the best way out.