A bowl of fresh flowers is enough. You don't need neon zodiacs and other accoutrements either. A few discreet charts, a nice planisphere, a reproduction celestial map, even a globe of the world, your certificates and a couple of pretty astrological artifacts are nice - a roomful of then make it more like a craft shop than a consulting room. Make the place fresh, clean, friendly, businesslike and above all comfortable. Keep the kids dogs and cats out of it.
Touch is always important in making a contact.
If you are a toucher by nature don't overdo it. Have tissues available. A lot of clients cry. Dress nicely - track pants are not suitable nor do you do the profession much good if you have too many dangling zodiac signs hanging round your neck. Give your client something when he leaves - everybody likes a little something to carry away.