You should only wear a white jacket if you're A. wearing a tuxedo B. Miami Vice.
But to the OP, it really depends on the person wearing the clothes. There are many factors to look at: their persona, whether they're 20's or 40's, slim or bulky, and etc. Style has a lot to do with the entire package of the person.
As an early 20's male, I probably couldn't pull off the WASP/Northeast prep look Spermie proposed. But it looks like your bases are covered if you are indeed pursuing that.
For a sporty early 20's male, like myself, there are two very basic looks I prefer. In the summer, I like to wear a slim navy blazer with brass buttons, and a pair of white pants. This is a very classic summer look (sorry no pics). For evenings or the club, I have preference for a slim short length black blazer, a dark shirt/polo, and a pair of nice expensive looking dark blue straight leg jeans(with a bit of a tapered leg opening).
These days, I like to play around with scarves and blazers/sport jackets. Like Mick Jagger has shown us before, a scarf can carry an entire look.
Look at the proportions, the sleeve lengths, and the scarf -- perfect. Though, I do not necessarily advocate wearing black blazer with white pants, unless if you can put it together as well as this gentleman.
The scarf here pulls the entire look together. Don't be afraid to wear bigger/longer scarves.
Can you tell me what's wrong with this picture??


