There's a time in a young man's life that one should own at least one tailored suit jacket or even a tux. Nowadays, both are not exclusive to fancy soiree anymore. Most men spend hundreds of dollars on a nice dinner jacket only to be worn a handful of times. Nowadays, a nice sharp jacket blazer is worn by fashionistos when they are out and about in town. You can dress it down with a pair of nice jeans or slacks. Wear a plain t-shirt or a casual button down with it. Be creative on how you dress it down, experiment and accessorize, don't be afraid to urbanize your look. I think some pointers to remember is to get a blazer that is slim cut or european cut and keep it classic. You NEVER want to look like you just bought the entire outfit from the runway to the street. No Bueno.