Summer is a wonderful season and, in order to completely feel relaxed, you have to dress comfortable. Ideal would be to have a chic, relaxed but comfortable outfit. In this respect, you could try a pair of denim shorts and a white T-shirt. It might seem a too simple combo but trust me, it is of great effect. Many times, simple is better. This combo is very chic and practical. Be careful at the accessories because you should avoid exaggerating.
Denim shorts:
T-Shirts: