I just moved into a new house and I have a new room to decorate. I really want to showcase an ambiance of calm, relaxing, safe, yet arousing and curiosity effect. I've been throwing a few ideas around like an underwater theme and stuff like that. Any suggestions on a theme or cheap stuff would be of excellent help.
I think whatever you do, whatever style you go with, lighting is so important. If your bedroom has too function as a study/office too, you need to make sure you have good light for work, but that when you turn that off you have a nice, soft, cozy/sexy atmosphere (No, not dingy! ) Try to use multiple softer seperate lights to light your space than one really strong one. I really think the wrong lighting will destroy the atmosphere of any theme! Other than that, let your personality shine through. Try to plan ways to keep your mess out of sight (we all get messy sometimes - but the appearance of no mess/clutter goes a long way to help make a place relaxing and calm), even if it exists (boxes, closed shelves, etc). Good luck!
It's not the whole answer, but how about adding a lava lamp? You know, like the ones that were all the rage in the 1960s and 1970s? You can find them cheap at flea markets and junk shops. They exude "calm", "relaxing", and "safe" vibrations, yet they are kind of arousing, in their own campy way.
You can find cheap but very nice and interesting decorations at Ikea with a relaxing effect. Buy couple black and white paintings, or even a nice modern canvas, maybe few vases, a candle holder, a nice lamp. It's really affordable, and they have plenty models to choose from.
If you want a preppy sexy- (my favorite) I would suggest pottery barn. The Classic Stripe Duvet Cover & Sham comes in really calm blues but is totally cute. The Hundi Lantern was designed to look relaxed and peaceful. For a vacationy chic but really sexual go for the Ralph Lauren Home Cape Lodge collection. The neutral tones and medium wood can make any room look well put together, classic, and of course hot.