Because my Thai partner can negotiate for me and I go to a tailor who doesn't speak English and thus has few Western clients, I probably get as good a deal as any in the city: 4000 baht for a two-piece suit, 5000 for three pieces, and about 500 baht for a shirt. All custom made to my specifications, and he does a superior job, better than a $2000 tailor in the U.S.

In Bangkok, the practice widely accepted by many tailors is to buy the fabric separately on your own rather than from the limited selection the tailors have on hand, which is often just stock for the 24-hour tourist. The many textile shops in Chinatown have a fairly good range of fabrics from which to choose. Assuming you are average height, average weight, average build, you need three meters (of 60" wide) fabric for a two-piece suit, or four meters for a three-piece suit. If you want extra trousers (an up-sell item in all Asian fabric and tailor shops), you'll need about an extra 1.5 meters. For shirts, you need 2 meters. A practiced eye and experience helps in discerning what fabrics will feel and look good once made into suits, which is not that easy to tell just by seeing and feeling the fabric on the bolt. The Super 100's, 120's, 150's business is a decent yardstick but by no means the sole indicator of quality. Although some poly blends can look and feel perfectly good, you'll probably favor the 100% wool materials, or those blended with silk or cashmere, which can be very luxurious.

In my experience (over the course of three recent trips, I've had 19 suits made for myself and three more for a friend), the best selection of fabric is not in Bangkok but in Singapore. Last time, I bought all of the fabrics in Singapore and took them to my tailor in Bangkok to have the suits made.

As for designs, in Bangkok you can 1) choose from the pattern books or magazines the tailor has on hand, 2) bring your own items to have them copied ("same same, this fabric"), or 3) bring a magazine spread and have the tailor do his best to create a garment based on the image. My tailor has done a superior job at all three tasks.

Finally, this may be obvious but is a good reminder anyway, it's generally the best practice to visit your tailor on the first day of your trip in order to give him maximum time to work and schedule fittings for the end of your trip.