I don't recommend bean bags, i got them for my preteens, and they never used them, ever. I suggest going to Ikea, or if your budget is higher, to similar high end store. There are framed photos, nice cheaper carpets, clocks, lamps... One place I found a ton of nice things is Life4Animals Thrift shop. I almost don't want to give this shop out, but it is awesome with ton of cheap but nice framed pictures, old lamps, corner tables and no crap stuff like some other Thrift shops carry.

Get fatheads. My boys love them.

No tv or computer in bedroom. My daughter can use her laptop in her room for homework but that and the phone get plugged in downstairs by 10pm.

Beanbag chairs
Posters
Sports memorabilia
bluetooth speaker
full length body pillow

If you do want decorative, you could take a picture of some thing/activity/etc. that the kid loves and have it made into a large canvas. (We did that for my son for his area of interest and he really likes it.)
I also like the Cardboard Safari animal heads, which are kind of fun décor that is not too girly or babyish.
Etsy also is a great source for things like pillows with quotes from their favorite movies or silkscreened images of their favorite things.

We bought a beanbag chair for one kid's room from Pier1 and we love it. Everyone in the family wants to sit in it; we may buy another for another kid's room soon.

No computer or TV in the bedroom.