With the canopy, you don't really need a shower curtain, but if you go that route in lieu of the canopy, hang elegant curtains on each side of the tub and catch them with tasseled drapery tie-backs tacked or hooked to the wall. Consider the lighting next. Nothing sets a mood more effectively than the low, calm glow of candles - especially when they're flickering against a tile wall or through a heady cloud of steam. Use them generously, yet judiciously, spreading them around the room in an artful manner. But be sure to position them to avoid sooty smoke stains on curtains or wallpaper.
Flowers are another scene-setter.
Buds with full heads like lilies, orchids, peonies and roses make a bold and beautiful display. Sensuous aromas complement the spa experience and contribute to the romantic mood. Essential oils of jasmine, patchouli, ylang-ylang, rose and sandalwood are known for their aphrodisiac powers. Mix them with water and spray them in the air, or add a few drops in the tub. And many essential oils have other qualities.