You need a shelf or two to set stuff like the diluted soap solution/conditioner/rinse on above the sink whilst you are doing the deed. A towel bar beneath that shelf would also be useful so you can put blotting towels on it for right after you are done. A tub that is flat bottomed yet no deeper than a kitchen sink but wider and longer than a kitchen sink would be my ideal choice--I don't know if they make them like that however. (To save your back). A swivel spray arm and Hot/Cold handles that are easy to adjust are important.