Most waistcoats have an adjustable cinch in the back, but some have buttons. If your vest has buttons, all you can do is fasten them to adjust the fit of the vest. [2] X Research source

If the two sides of the belt are already attached, all you have to do is pull the loose end to tighten the belt or slide the cinch to loosen it.

The belt’s righthand side should always stay on top of the lefthand side.

Do your best to keep both sides of the belt as flat and straight as possible.

When your vest is on, reach back and pull the loose end of the belt to tighten it more if needed. [7] X Research source If there are wrinkles along the sides of the waistcoat or if it’s hard to breathe, you’ve probably made it too tight. [8] X Research source

If you’re going to tie a knot, consider trying on the vest a second time to double-check that the fit is right. It’s easier to make adjustments before the knot is in place.

This technique is especially helpful for slipperier fabrics, like silk, which are more likely to slide out of the cinch without a little extra reinforcement.

The vest’s top button is optional, but all the rest should always be fastened.

Some experts say that the top 1 in (2. 5 cm) of your waistband should be covered, while others say that your vest should cover your entire belt. Decide which look you like best and wear it with confidence! Don’t forget that you can always get your waistcoat tailored if you need to. If your vests are regularly too short but fit well around your torso, purchase the next size up and let a tailor take the vest in so that it fits perfectly.

If the shoulders of your vest don’t fit well, there’s a good chance the rest of your vest might not fit right, too.

Avoid wearing T-shirts, sweaters, or polos underneath your vest (and you should never go bare-chested underneath it, either).

If you do wear a double-breasted waistcoat, make sure your suit jacket is single-breasted. Double on double tends to look overdone and clunky.

For a classic styling of a waistcoat without a suit jacket, wear the waistcoat with a matching pair of suit trousers. This will create a sense of uniformity. If you’re committed to making your waistcoat part of your everyday-wardrobe, choose a knitted one. It’s a nice blend that looks more casual and is easily paired with trousers and a blazer, even if they don’t match perfectly.