Looking for 16 year old girl's bedroom ideas and decorations. Please help :)?

I'm 16 and i'm re-doing my room. I got it re-done when I was 8, and I chose lime green and sky blue. I'm older and those colours seem a little kiddish for me, so I've chosen to re-do my whole room. I have no clue what to do, I just want something older, mature and modern that all my friends are amazed by. I'm not rich, but I have a limit of fair amount of money to spend on this. It's kind of a birthday gift. I know everybody says to pick your favourite colour and start from there, or bedding, but I don't really have one. Every idea I find on the internet I seem to like. For example, I like the idea of a green grove brown for the walls, vermilion red for the bedding and a light grey fleece blanket together, and maybe some photo collages around the room. BUT I also like a manchester tan for the walls and turquoise hawaiian flower themed bedding and antique furnished furniture around the room to match. Does anyone have any ideas fore me to start off with? I play and I like hockey and basketball for sports, but I'm not obsessed with them. I also enjoy horseback riding and summer, and hanging out with my friends. I do most of my homework in my bedroom, so maybe a corner desk would be nice? My room is pretty small, it's 9ft long and 8 ft wide, and I have a double bed so there's hardly any room. Please help me figure something out :) Sorry for the long paragraph, just trying to give details.