Front tucking a long shirt helps you define your waistline and lengthens your leg line without the bunching that can happen from fully tucking in a shirt. Here's the trick to getting a perfect, sharp tuck every time.
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A crisp line along the bottom of your tucked shirt is key because it gives you a neat hemline that works well in professional or business casual settings, or when you want a more clean look. The key is to fold the hem of the shirt under before you tuck it into the front of your pants or skirt. Make sure the folded hem is neat and straighten the exposed hem after you front tuck it to achieve a cleaner line. If your shirt is still bunching after you fold the hem under once, fold it under twice before tucking it into your pants.
How (and Why) to Front Tuck [Alterations Needed]