Tailor your threads
Oversize clothes are unflattering on anyone, especially bigger men like myself. To make it worse, poorly dressed individuals are viewed as dismissive, less confident, and unprofessional.
Luckily, all it takes is a trip to a tailor and a few small alterations to set some things straight. Gather your ill-fitting clothing and visit an expert in your area. He should measure you from head to toe and provide a list of the final numbers to take on your next shopping excursion. In the meantime, have the tailor apply your measurements to the clothes you brought in.