Hi,

I'm redocorating myself and what I plan to do is paint one wall in my living room pink and put a Buddhist monk robe I bought in China on a curtain pole on it. The robe is yellow and I think it will look great. You could do a similar thing with a great dress or something. 

I just read about a similar service where you can create really big pictures from a small one: blockposters.com 

Somewhere I had seen that someone made a nice large bit of wall art with cut off bits of PVC pipe glued together, then painted. It looked pretty sharp. If you have a cutoff saw, that would help. :)

Another thing we have done is to scour second hand stores, and snatch up any large canvasses, no matter what is on them. you can paint right over whatever it is, and the more relief the better, in my opinion.  

I was in the same position as you when I redid my bedroom, and instead of settling for something that I liked, but didn't love, and would cost a lot more money than I wanted to part with, I deicded to roll my own.

I used a 24" wide interior door as the canvas (I only wish I'd gone with the 30").  I started by laying down a thickly textured layer of joint compound.  Once it dried and went at it with the paint.  Originally I planned to do a Jackson Pollock rip off, but I quickly discovered that there's a lot more to Pollock's work than just dripping paint.

In the end, I decided to focus on the texture and I'm really happy with the result.  Final cost, $40.

As for the sculptural stuff...  paper mache is always fun.  I've been dabbling in that lately as well.

Whatever you do, have fun with it and be proud of your work.