This casual pairing of a black crew-neck t-shirt and navy jeans comes in useful when you need to look sharp in a flash. Finishing off with a pair of grey athletic shoes is the most effective way to inject a laid-back feel into your look. Embracing the winter months will be super easy with such ensembles as your style inspiration. Ideal if you're on a mission for some amazingly inspiring relaxed casual style for 30-year-olds.