Mastering the menswear game can be a headache for even the most sartorially switched-on. So, if trend-hopping from one season to the next leaves you in a spin, why not look backwards for some style inspiration? Here we break down five timeless style tips and grooming techniques from the '50s, a decade dominated by kings of classic swagger Elvis Presley, James Dean and Marlon Brando. Take a look…