Esquire used to be my favorite magazine, once upon a time. But these days it has devolved into a sort of masculine-manqué manual for those newly arrived to New York.
They published a list of 75 things a man should know or be able to do
and #12 was How To Buy A Suit. The problem with the advice is that it's mostly "sound and fury, signifying nothing" and anyone who goes by the strict letter of it will likely wind up ill-suited.
I'm going to help you out. If you're a regular, chances are this won't be so bloody new to you, but in case you run into someone who may profit from this, you may want to print this out and hand it to them. It'll seem more authoritative than your telling them the same thing because, as we all know, no prophet hath honour in his own land.
Of course the simple and sensible thing to do is sprint to a tailor accustomed to arraying civilized gentlemen, but that is neither quick nor inexpensive. Still, there is something to be learned from them as you go purchase suitable raiments.
The single most important matter in selecting a suit is its fit, and the most important aspect of fit as relates to the jacket is the shoulders. Pretty much anything else "wrong" with the jacket has a remedy, but if the shoulders are off, no amount of tailoring will set it right. In fact, you'd probably spend as much as a MTM* suit in trying to fix this in vain. So if it doesn't fit your shoulders let it go and never look back.
Now, as far as fitting your shoulders go, there are two factors to keep in mind: width and pitch. Width we all know (or should
, you caveperson) about: the shoulders should be wide enough for you to hug yourself, but not so wide it looks as if the epaulets are stitched on the wrong side. Pitch is something a bit more difficult to pin down. Basically it's how the jacket's shoulders slope as you get further away from the collar.
The cheap way to do this is to go in a straight line, regardless of what ideas your own collarbones may have in mind. In order to look good you need to stand ramrod straight at all times which, unless you have some spinal condition or nervous tic carried over from military school, you won't be able to do for long. Your shoulders have, to one degree or another, a measure of, well, slouch. Your jacket's shoulders ought have a similar curvature. Incidentally, when it comes to shoulder pads, you want almost none on your prominent shoulder (right, if you're a righty, left if you're a lefty) and just enough on your opposite shoulder to make the jacket symmetrical.
Delving deeper into the "bones" of the suit -- and I'm sorry, this simply wouldn't photograph well for me, so just play along -- the armhole (or scye) should be shaped like the silhouette of an egg. This is to afford you maximum freedom of movement with minimal fabric and padding and all that. With ready-made stuff this is less likely, so just aim for something as oval as possible. While you're at it, look at the way the shoulder is attached to the body. It should be obvious from the silhouette where the body ends and the shoulder begins. Like a tiny little speedbump. Look for what are basically very subtle pleats on the shoulder, this indicates it was sewn by hand and will have a more yielding (i.e. comfortable) feel than something hacked together by machine.
There are many touches that distinguish something worthwhile from something so-so. Look at the lapel. Its width should be such that if you kept going straight from its outer edge it would neatly bisect the width of your shoulders. If it swallows up the pocket square it's too broad, if it reveals all of the breast pocket it's too small. Look behind the lapel. If you see a little loop of silk to hold the stem of a flower in place, it means the tailor took extra care to make this jacket. Never mind you'll never wear a flower, someone who has bothered so much with an invisible detail will have really sweated out the big stuff. This is good.
Now look at the breast pocket. (It's a crummy picture, so make an effort, will you?) Most of the time it will be a perfectly oblong strip of fabric perfectly parallel to the floor. Ideally it will slant slightly downward from the shoulder side to the chest side, and even more ideally, will be "boat shaped" meaning the outer seam will be, instead of a pair of right angles, a +/- 75 deg. at the top and 105 deg. at the bottom.
Move over to the other outside pockets. Now, I happen to like the smaller "ticket" pocket, but it's OK if you don't. (You are under no obligation to maximize your stylishness.) Note the pockets flare slightly at their rearward edge. This a) keeps them tucked in when you want to go for a more "continental" or sleek look and b) make it easier for you to work your way inside the pocket to reach for something. This is another of those details that add up.
Now flip the jacket inside out. The more handstitching you see (you can tell because the stitches will be visible and ever-so-slightly irregular, as opposed to the invisible precision of machine-sewn) the better. There are two ways to go on the inside of the jacket. One is a half-lining, which is pretty posh because it requires all of the exposed seams to be neatly finished, which adds hours to the garment which jacks up the price. The other is with a full lining which can be pretty posh, if you select silk over the more pedestrian rayon, for example. I tend to lean towards a full lining, because it makes for a smoother dressing experience and less friction between jacket and shirt as you sit, move, turn, etc.
If you look carefully, you'll note those little touches...a pen pocket, for instance. Or the interior pockets fastening with a button and loop which is cheap and easy to replace were it to fray or tear (as opposed to a buttonhole on expensive silk lining, which isn't either).
Turning the jacket right-side-out again look at the sleeve cuff. In a custom/bespoke/MTM jacket, there should be working buttonholes -- this is so that you may wash your hands without having to take off your jacket -- and this means if the jacket sleeves match your own (i.e. they stop just shy of your wrist bump) the garment was made for you exclusively, blahblahblah. This sort of sleeve in pretty unalterable, which means the jacket is not really wearable by anyone else. Yes, I s'pose you could detach the sleeve and reattach it at the correct length but for the expense it would run you you might as well get a MTM suit.
Anyway, some off-the-rack (or off-the-peg) jackets will have an open seam at the sleeve that it may be altered to fit you and then have buttonholes cut thereinto. Go for those if you can find them and they fit your budget. Do not, of course, go for those which already come with working sleeve buttonholes.
When it comes to trousers, the crucial fit factor is the waist. Easy enough. Not just the size of the waist, but how high it sits relative to your own natural waist. Ye Olde Classiques used to sit fairly high up, say, at the navel latitude. The European stuff sits, jeans-like, at the hip. Go for the Goldilocks effect and aim for something that sits at just below your navel. Given that our waistlines will fluctuate somewhat no matter what we do, and given that belts are far too much the hallmark of a sartorial rube, you want some sort of side-tab adjustment. There are two kinds, the slide-tab and the button tab. The slide tab has the advantage of being infinitely adjustable, but the disadvantage of needing not-infrequent adjustment. The button tab (featuring 2, maybe 3, buttons per side) is set-and-forget, assuming the buttons are sewn in the correct spots. I like the button tab arrangement better. Also, if something went awry, I could sew one of the buttons back on...dunno I could work my magic on the slide mechanism.
Incidentally, you needn't opt for suspenders (or "braces") but they do add a serious touch of style.
While we're down there, look at the front of the trousers, where everything fastens together. There should be something called a French fly (now, now class...) which is basically a longish, diagonalish tab that is affixed with a button on the inside of the waist. This keeps any extraneous bulges to a minimum, lest the little old lady whom you help to cross the street thinks you're particularly happy to see her.
Once you're all buttoned up -- or zipped, your call -- we get to the matter of pleats. You can't really see it clearly in the picture, but these trousers have their pleats opening up towards the center or "inward" pleats. 99% of all the pleated trousers out there are OUTWARD pleats (i.e. opening up towards the hips) and these are wrong. Flat-front trousers are really only flattering on the slimmest of men (31" waist, at most).
The legs of the trousers should taper gently, like your own legs do. Flared, straight and pegged trousers are all wrong. Figure the width at the knee of +/- 22" and +/- 19" at the cuff. Oh, and speaking of...the trousers must be cuffed (except for formalwear): 1.625"-1.75" depending on your height. (The taller, the cuffier.)