Retro style is a culturally outdated aged trend/fashion from the overall post-modern past that has made a come back in recent times. So, do you have some old clothes you haven't worn in forever. Probably your mum's super cool outfits of then. Its time for you to dig it up and get it clean. If you don't have those, you might as well head to cloth stores and purchase yours because it is time for us to re-invent the past. Some pieces you might need include scarfs, patterned tops/skirts/trousers, wedge shoes, crop tops, high waist trousers e.t.c. Feel free to combine modern pieces with them.