I would suggest one focal point wall painted John Deere green with huge logo painted on the wall other walls neutral. Maybe sleek black furniture , black rolling toolboxes for night stands, etc. when he gets tired of John Deere then just paint over the accent wall and you're ready for the next theme.

Start with looking through photos and saving them the ones you like by adding to your ideabooks.

I'm feeling i'm flying blind here. But here i go. What are your interests and hobbies. For example, i always like hiking. To make hiking more interesting i got interested in mineralogy, and thus added shelves to display my mineral/rock findings. P.S. Trumbul, CT, USA has up to 32 different types of minerals...topaz included

Hi Bradford Rice, I understand that it can be difficult to decorate for someone this age. The best place for you to start is to specifically ask him some leading inquisitive questions like, "What do you like to do most?" "Whats your favourite part of your room and your least favourite?" If you can find an item which is dear to him (like his guitar, or playstation remote; yes I did say that! or favourite sweatshirt) then this gives you a springboard to build from. There are some amazing wallpapers out there (check out Mr Perswall graffiti range, or distressed timber board wallpaper) which without too much investment can transform a room quickly. Try to simplify your colour palette and limit it to just a couple of colours, dirty pinks are in vogue along with greys, and animal skins, remember that bedding colours bring a whole new feel to a room and if it lacks natural light keep the colours masculine but subdued with a taupe linen bedspread. Incorporate some chunky texture if you can by way of a thick weaved carpet rug or woven rustic lamp shade, and some shelving storage to encourage him to pick his stuff up off the floor! Good luck with that one! Post a pic if you want further advice.