For an ensemble that's super straightforward but can be manipulated in a myriad of different ways, opt for a grey polo and yellow chinos. You could go down a more casual route on the shoe front by finishing off with a pair of sandals. This ensemble is a never-failing option if you're looking for a great, summer-friendly ensemble. Those who are curious how to wear modern casual dressing as you head into your 30s, this combination should answer your question.