One button suit - always buttoned when standing and unfastened when sitting and of course this holds true for every other button style suit as well.

Two- button suits - always button the top and never the bottom. Suits are designed in a manner where the bottom button is meant to be left open for proper fit and drape.

Three - button suits - button the middle. You have the option of buttoning the top if you like but never the bottom. If the lapel rolls down to the middle button, then only buttoning the middle button would be correct.

Four or more button suit - often seen on celebrities, this suit is more of a fashion statement and definitely not a suitable option for formal business environment. But, if you do ever feel overly adventurous and want to make a brazen fashion statement, remember to leave the bottom button undone.

Double breasted suits - remains buttoned at all times untill you take the jacket off. Fasten every button, except the bottom but you can choose to button this one as well, following Prince Charles style.

Jacket sleeve buttons - a mark of quality. There are traditionally 4 buttons that sit very close together, touching each other slightly, on the sleeve. You may also find 3 buttons on the jacket sleeve.  Also known as the surgeon's cuffs, the buttons should be able to unfasten and allow you to roll the sleeves up as they were originally menat to be functional and not just a detail on a suit, as it is today. But unfastening your jacket buttons might make you look like a show-off. Therefore, these buttons are best left buttoned.

Happy reading.