For trousers go for negliible pleating. If bottom is broad, some pleating will be comfortable. Check trousers effect without a jacket to get a flattering style. Shirts and collars would be similar to the Inverted Triangle. If neck is short or thick though, keep away from Oxford cloth and button-down collar.
Shoulders are more narrow.
Dont wear a suit that is too snug in fit. Try for a Modified European cut suit which will artificially extend the shoulders to balance the hips and project more strength. Peaked lapels create a broadening illusion of the shoulders. Ties need some width, but still need to be fashionable. Narrow ties will emphasise the narrow upper body, so avoid them.