There are some simple rules for your suit buttons
Very simple, and yet you see lot of men doing it wrong. Don’t be one of them.
It is a two-button suit? Only button the upper, never the bottom button. Never ever. Or leave both buttons open. The same thing applies for the three-button suit, never button the bottom button, but in this case always button the middle button, the top button is a free choice. If you wear a double-breasted jacket, make sure you always button the so-called anchor button. (The extra button hole and button on the inside of the jacket). And here, always button the middle button but never the bottom one.
And a last advice; when sitting down, always unbutton. Always. If you forget that, apart from looking corny and stiff, you risk ruining your suit or even popping a button. Be comfy and calm. The only exception to this rule is a single-button jacket.
By the way, everyone can of course button as many buttons as he likes, but if you want to follow the classic rules and know some style history, these are the rules.
The “Sometimes, Always, Never” button rule: