What is the size of your room maybe I can do a visual for you

How old are you? You can start by making your bed on a daily basis. My son is 12, and he is not allowed to leave his bed unmade.

Can you take pictures of the remaining walls? Do you have your desk in there as well? Or other furniture we don't see? Is there a reason the dresser is overlapping the window? It's a nice sized room, with lots of potential.

yup, it looks like my kids rooms did when they were teens, so i'd say you are already successful. no need to change a thing.

something purple..check. something zebra ...check. fairy lights..check. heart decor.. check. you even have a nice handbag collection.

My daughter has done a great job with her room. She has a lot of knick knacks and favorite things she keeps out. She doesn't like her friend's room that looks like it came out of a magazine. So make it yours. She also has a bed cover, window covering and rug that work well together. She found them in different stores or websites. She was able to get them for Christmas and birthday presents. She has some of the same things hanging as you. I would say to lower your wall decorations and group them. My favorite thing about your room is that it reflects you! I am going to find some examples and post them. Look for rooms on line and get ideas from your friends.

ninogret is right. My daughter has all those things too. She is also picky about furniture placement. She likes to try new arrangements ever so often. You can learn about that online too. I found a blog for you about photo mural and display walls. http://www.gurl.com/2015/01/30/awesome-diy-photo-collage-ideas-for-dorm-bedroom/ Have fun!

Part 2 of this article gives ideas about furniture placement. http://m.wikihow.com/Arrange-Bedroom-Furniture

Not certain I am able to see all of the walls in your room. First I would arrange the furniture differently. More your bed so the headboard is under the peace sign. Move chest of drawers on wall at end of bed. Place tv on top of chest of drawers--if this will work. Move tv stand beside bed as a night stand. Take lights off bed and run from ceiling over headboard. (Can staple over wire, but not in wire or use push pins). Be sure to use enough strands to cover wall over headboard.
Hang bulletin on same wall, but closer to window.
Hang initial"S" centered over bulletin board. Use pictures to outline bulletin board. Hang pink metal pic to right of window. Move mirror to right of purse/cap rack. Hang black/pink hanging on closet door or closet doorknob or on wall over night stand-- leave room for lamp. Perhaps hang Disney picture inside closet. If using the color shot pink. Black, teal, I would remove all the purple items. Hang sheets on window. Look at Walmart. Target, etc for lamp, chair word pictures.
Housekeeping next! Place laundry basket in closet until empty. New sheets in white, hot pink, teal, black or something that coordinates with these colors are needed. You can use the sheets as your bedding or get a comforter. Use both bed pillows on bed and accent with the teal and white furry pillow. Place small bear on bed in front of pillows. Use other real pillow in chair. Place chair in corner by window. Rocker can stay where it is or go by chest of drawers. When find two word pics, hang on wall on side of bed with peace sign in center of them. Dollar Tree sells a pkg of pennants you could hang round ceiling in room.
Hope this helps. You could look on line at "teenage girls bedrooms" or Potter Barn for teens to get some other ideas.

Not sure I am seeing pictures of all of your room. Try turning bead so headboard is under peace sign. Move chest of drawers to wall at end of bed. If tv will work on top of chest of drawers, put it there. Use tv stand as a night stand by bed. Remove lights from bed. Hang the from ceiling vertically over bed ( You can staple over cord at ceiling or use a push pin. Allow lights to hang freely. Move bulletin board closer to window on same wall.
Hang it vertically if possible. Hang initial "S" over bulletin board.
Outline bulletin board with photos. Move mirror to right of cap/purse rack. Hang pink/black quote on doorknob or over night stand. Leave room for lamp. Perhaps move Disney item inside closet....if keeping. Hang pink metal piece by chest of drawers.
If you are going to use hot pink, teal and black for your colors, perhaps need to change out purple items. Try white sheers on window. Check Target/ Walmart for one of the fuzzy , bowl looking chairs in hot pink, teal, or black. Find a lamp in one of those colors or white. Look for two word pictures or signs (Dream, live, love, etc). Place these and your peace sign on wall to side of bed. Find a comforter to go on your bed in one of these colors or something that coordinates with the colors. Even a white comforter would work. Find set of sheets in one of these colors. Use both bed pillows on bed, use one of different colored fuzzy pillows on bed. Place small bear in front of pillow. Place other teal pillow in your chair in front of window. Rocker can remain by window or by chest of drawers. If you can afford it purchase a larger solid rug, and place zebra rug on top of it.
Put laundry basket in closet until you can empty it.