This writer might be a tad biased towards a monochromatic look, and this one gets it right. The olive-green blazer and matching trousers give the outfit a sharp, put-together feel, while the white vest keeps it relaxed and breaks up the colour. 

The layered golden chain and chunky watch add just enough detail, without taking away from the outfit. Rolled-up sleeves make the tailoring feel less formal and give it an easy, off-duty touch.