Smell: I advise using essential oils in an ultrasonic diffuser or in a candle diffuser (most wax candles these days are packed with synthetic fragrances). Limit it to a few drops of oil in diluted in water, and don't leave them diffusing for more than an hour or two. They are potent! I love lavender and jasmine oils for a calming smell before bed. If I have a cough, I'll go with ravintsara or eucalyptus. Looking to amp up the sexual energy? Check out cinnamon, ylang-ylang, and best of all, winter savory.
Touch: In the bedroom, it's best to go with soft, inviting fabrics when possible. I'd recommend velvet, satin, and Egyptian cottons for all sheets, pillows, cushions, and curtains. Your bed sheets should feel particularly soft to the skin.
Sight: As I mentioned before, Earthy tones are really what you want to be seeing in the bedroom. Fiery tones (reds, pinks, and oranges) can also be nice in moderation. Again, these accents should always be presented in pairs. In my bedroom, you'll find a pair of small pink Mandarin ducks—a traditional Chinese symbol. I love these because the story goes that the ducks were always faithful to each other. Find accents like this that speak to you.
Sound: I'd recommend a small white-noise machine to play soothing tunes.
Taste: While I do not bring food into my bedroom, I always make sure to keep a small jar of water next to the bed. Place some lemon in there and drink it in the morning for a quick boost.
You'll also want to consult a Bagua map to see what elements to pull into your space. Locate what Bagua your bedroom is located in relationship to the front door of your house, and add accessories accordingly. For example, if your bedroom falls in the Health and Family area, where the dominant element is wood, try to incorporate greens and blues in order to sustain that element.