The Human Empire is a design and illustration studio that works for a lot of interesting and international clients, lots of them come from the fashion-, music-, art- or culture-section. For example they designed for a lot of musicians including Feist, Deathcab for Cutie or Architecture in Helsinki. They do good stuff, which you may see on their website.
Since 2007 they run a small store in the Schanzenviertel. You can buy creative things there from posters to clothes and books and accessories.
All posters are created by young and aspiring international illustrators, graphic designers or artist and so are most of the clothes. Meanwhile they carry some interesting international fashion brands which are not easy get in hamburg such as Happy Socks, Sitka or Rvlt and hence Sandqvist. The books they offer cover the latest in design, typography or illustration, furthermore they have a beautiful selection of kids books and accessories. Prices are very affordable; you can buy posters from 10 EUR.
I go there whenever I need a special gift or just to buy myself new stuff for my walls or for my collection of design books. You will love it, if you are into in design and creative things and fashion.