A new suit is a wonderful thing. If it fits right, if it’s well made, then slipping into tailoring is like shrugging on confidence. You feel more attractive, more secure in your decisions. And other people can see the change. Unless, of course, you forget to deal with these little details. Don’t look like a n00b.

You Don’t Cut The Vent Threads

A vent is a slit up the back of your jacket. Like all manner of menswear details, they’re leftover from the suit’s time as uniform – it let the jacket sit over a saddle without bunching. Italianate tailoring tends to be single-vented, whereas British suits prefer a slit up each side.

Whichever style you pick, at first wear they’ll be tacked shut by a small ‘X’ of thread, which stops the fabric getting rumpled up when it’s being shipped or hung in store. Slit these before you wear it or that X will make the spot where your panache died. Your new jacket also won’t sit properly, since the material will pull around your seat. Which is doubly embarrassing.

You Do Cut The Pocket Threads

As you’ll discover when you first try to stow your keys in your jacket pocket, the factory sewed them shut. Again, that’s to make it look better on the rail; the fabric sits flat and the men who try it on can’t stuff their fists in the pockets and stretch the jacket out of shape.

Leave them shut. Because otherwise you’ll be tempted to stuff your fists in there and stretch your new jacket out of shape. You shouldn’t ever put anything in your outside pockets anyway – it makes the fabric bulge and hang lopsided – and the thread will allay that temptation. Although if you’re a pocket square guy, feel free to open up your breast pocket to make space for a silk. But never a phone.

You Leave Your Functioning Cuff Buttons Undone

If you are wearing an expensive suit with surgeon’s cuffs – that’s functioning buttons on the sleeve – your tailor might advise you leave the last one undone. Working buttons have long been a feature reserved for spendy tailoring, since they take more work and skill than just attaching a button to solid fabric. By leaving the bottom one open, you let everyone know just how much your suit cost.