For an outfit that's very easy but can be smartened up or dressed down in a myriad of different ways, go for a camel overcoat and grey check chinos. For something more on the smart end to round off your look, round off with a pair of tan leather double monks. As a gentleman in his thirties, you probably want to start dressing more professionally. If that's the case, outfits like this are a foolproof option.