This casual combination of an olive crew-neck t-shirt and navy chinos is a surefire option when you need to look laid-back and cool but have no time. If you want to immediately tone down this getup with a pair of shoes, why not complete this ensemble with black leather flip flops? You actually can look cool and fresh under the sweltering heat. The proof is right here This getup should clear any doubts you had about wearing casual clothes as a 30-something gentleman.