I cannot believe I have been in this business 10 years and have never thought to address this question. I guess its one of those blind spots you have when you do something day in and day out; you don’t consider that others are new to it.
So here is the answer- you can wear almost anything that is LOOSE FITTING and comfortable. Wide leg jeans, wide leg yoga pants, shorts, skirts, dresses and any kind of short sleeve shirt are generally good choices. Skinny jeans, leggings and turtlenecks are not. In order to receive treatment, your acupuncturist will need unrestricted access to your lower legs, lower arms and sometimes your neck and upper back. If pulling up the legs of your pants restricts your tissue, then your blood flow will also be restricted. Since one of the main goals of acupuncture is to improve your circulation, we do not want to start off on the wrong foot (or leg!) by having to fight with your clothing for optimal circulation. I even heard an acupuncturist say that pajamas are the perfect thing to wear for treatment! This can serve double duty since the majority of acupuncture patients take a nap during treatment anyway.
If you don’t typically dress in a way that is conducive to receiving acupuncture, then I recommend leaving a short sleeve t-shirt and a pair of shorts in your car so that you may change when you arrive for your appointment. That way, you are always prepared.