1. Suit and shirt collar fitting
This rule, little known but very important, consists of never letting a visible space between the back collar of the shirt and the collar of the suit. Both must be adhered to each other. This is one of the signs that determines the quality and the precise cut of the suit. The collar of the suit must cover more than half of the one of the shirt.
2. Suit jacket: button rule
Keep your jacket buttoned, apart from the bottom button. It should always stay unfastened, unless you are wearing a one-button jacket. In this case, keep the single button fastened. This rule comes from Monarch Edward VII who could not fasten the bottom button of its waistcoats. He gave rise to this tradition that applies to suit jackets. This simple motion can help you look taller and lengthen your legs.
3. Necktie length
A properly knotted tie must scratch the belt buckle. Certain Italian men would rather let the back panel longer than the front one. Reserved exclusively for the bravest ones.
4. Sleeve lenght
A well-cut suit jacket should have sleeves between 1.2 and 2 centimeters shorter than the ones of the shirt, depending if you are short or tall. This is a fundamental rule that increases the length of the arm and the length of the hand. You should adapt this length according to your morphology.