How to suggest Decor changes in a shared living situation?

I recently moved into a shared living situation. My new roommates are great.. except that they have no concept of how to make a space nice. They are almost everything I could ask for in roommates, that said all I really ask for in a roommate is that they don't leave there junk around. Not a lot. The only thing lacking is there inability to see what a nice house they live in. I'm pretty sure they moved in 3 years ago, brought their crap in from the moving truck, put no real though into where to put stuff, and just set it down where ever and that's how it's stayed all this time and now they are used to it and quite content and happy with how it is. We have this massive floor to ceiling window that has a gorgeous view the cityscape and they've put a big clunky TV right in front of it. Interior design is something I really have a knack for and I'm planning a career around it. So it pains me to be in a house that I can see worlds of potential in but somewhat stubborn roommates when it comes to moving some furniture around and getting rid of a few pieces that I'm pretty sure were picked up off the side of the road (yuck). I am a good communicator in these situations, just wondering and hoping anyone out there has some suggestions on how to approach this, or maybe you've been in a similar predicament and you can share your story?