The Jacket
The jacket should fall perfectly around the shoulders without creating any creases and without the shoulder area sticking out. Towards the stomach area, the jacket should fit slimmer to make the shoulders appear broader. Only button up the top buttons and unlike regular blazers, double breasted jackets should always remain buttoned up; sitting or standing.
The Buttons
The buttons are mostly up to one's own desires, though most of the time, more buttons means more formal. Double breasted jackets are generally worn with six buttons, three down each side, but jackets can still be worn with up to eight buttons in total.
The Trouser
The trouser fit is also quite similar to that in a single breasted suit, but it also depends on what one is looking for in the suit. If you are looking for a classic and highly formal style then the trousers don't necessarily have to be tight to the leg, but if you don't mind going for the modern look then you may try wearing slimmer trousers while at the same time keeping the good aesthetics of the suit.
The Fit
Double Breasted
8
Wear PB
Double Breasted -Fit