You only need one item to take your casual wardrobe to the next level: a muscle-fit denim shirt. Double denim is back, so give it a contemporary twist by pairing one of our men's muscle-fit denim shirts with your favourite pair of jeans. It can work as an overshirt too if you layer it over a basic white tee. Add a bomber jacket and high-top trainers for an edgy look. A River Island muscle-fit denim shirt can be dressed up too – simply button the collar and tuck the shirt into a pair of chinos, then add loafers to head to a Sunday lunch at a fancy restaurant. Dark denim or light – we've got both.