Hi all, first and foremost thanks very much to everyone who have contributed in some way or another to this thread and I think I owe it to the many out there who have not explored the option of shirt tailoring in Bangkok to proceed with this post on my experience with Boss Avenue tailors on Sukhumvit Soi 7 (Nana BTS).
1. You need to know what you are looking for: Daily wear shirts that survive the grind of day-in-day-out machine wash VS dress shirts that should be handwashed for the occasional cocktail parties or smart-casual events. Thus I made the 850Baht shirts knowing full well that it is the former that I am looking for; the daily shirts with a fair bit of fitting and trivial customisations (embriodery of initials, underside of cuff having flowery patterns etc). Though I must admit that the 1,000-1,250 range shirts are of a better quality, they didn't blow my mind away as most of the material were quite thick and didn't seem to make sense to me when the hot and humid season daunts upon us coming February.
2. Budget: Knowing what you are looking for definitely aids with the budgeting. Based on the first-time experience, it appeared that Boss Ave's got 3 tiers of pricing - the 850b, 1,000b and 1,250b shirts + free customisations (huge plus if you're a fan of fancy needlework). Initially quoted me 900 but that's on the assumption that i was making one piece. Economies of scale does help to bring the price down; so if you are not interested in making more than 2 pieces i think it wouldn't even make sense to put down tailoring as part of your holiday itinerary. Why? Will elaborate more in the next point.
3. Fitting it into your holiday itinerary: 3D2N is a must for tailoring unless you bring along with you from Singapore a sample piece for them to replicate. Day 1 choose fabric + take measurements, day 2 go for fitting, day 3 collection. If you fail to go for fitting because you cannot slot it into your schedule, you are no better than buying your shirts off the rack @ Robinsons during Xmas sale. You have to make time for fitting because thats the whole idea behind tailored shirts. For the uninitiated, fitting in Bangkok tailoring context means fine tuning the initial measurements taken from Day 1; for e.g. tightening the sides to give you the 'slim fit', adjusting sleeve length, ensuring the collar buttons are comfy when you button them up etc. Therefore i personally think its a hassle to slot some time into your itinerary when tailoring is one of your travel agendas; so if you're not making a couple more shirts then it's such a waste as it might mess up your schedule/plans because they open at 10.30am on weekdays and usually at that time you'd either want to be visiting the tourist attractions/heading to chaktuchat market/rushing down to platinum fashion mall or going to yaowahraj (chinatown).
4. Do your homework before you go: it helps alot knowing what you want. deciding if you want different cuff style, french cuff, buttons, types of collars, need for customisations etc. one of the bros in here put up a really useful picture showing the types of cuffs and collars. this can really help to speed up the decision-making process as all you need to do is brainstorm on your colour and design of the material which is pretty much 60-70% cotton and remaining polyester. it helped me decide so i think it should help you too. Of course they have catalogues and magazine-like books on the table, flip a couple of pages and hope to find the type of customisation you want - it's easier to point to a picture and say "i want this" than to try explaining with weird descriptions.
5. Caveat Emptor: For the first timers, do manage your expectations. Don't expect '100% egyptian cotton' when you're only paying 850b. Service is manageable and not pushy, but don't expect CYC-type attentiveness. Materials are okay, but don't expect them to be presented to you in a professional album-type format, all their cloth materials are rolled up and shoved in shelves (similar to what buying plastic book wraps by the rolls from popular bookstore). Good luck and travel safe!