I would add that, even with the same tailor --and I am certainly not going to more than one at a time, for many reasons-- things change with time: the cutter will get a more precise idea of what fits you over several orders, so suit number 2will fit closer than suit no1, no 3 better than no 2 and so on... Also, he will refine his idea of what looks good on you and what you like (cloth weight, colour, etc...). Ditto of your tastes: with experience (ordering and wearing), you will acquire a better idea of what you like and what you think suits you (hopefully the tailor will agree...) and what you find useful.
A conscientious tailor will not want you to walk out with an ill-fitting suit. Mr. Munday (M & M/Jones Chalk & Dawson) likes me to wear a suit a couple of times at least , then bring it back for inspection. That led to one or two extra fittings on my first order, so he could tweak a few things. Time (for me) well spent.
Speaking for myself, many years ago, I used to hedge my bets and have trousers with both belt loops and brace buttons. Experience has shown me that I never
need take my jacket off in public so I have dispensed with loops and only get braces (with a fishtail ?? waist back). The exception: a navy blazer with dark grey trousers, now in process: the trousers will have both Daks straps and brace buttons, because I might conceivably take the blazer off in summer. Slanted pokets I found too limiting so I only have one tweed suit and one tweed coat with them, both more than fifteen years old and I will not get more (I know one should never say never...). I always get the same pocket arrangement on a DB suit. I always get a waistcoat with a SB, and that is always 3-button. I could go on and bore you into slumber, but you get the idea.
All this evolution is based on an exchange of ideas with the cutter. Ask questions, make hints, but do pay attention to the tailor's response. If you feel he is resisting, then do not push too hard: he is the professional and knows wherof he speaks! Mutual trust built over time is what this is all about. Going back to my earlier post, this is why choosing your tailor carefully is so important.
I have blathered long enough.
Frog in Suit