When you take the trouble to tuck your shirt in, you are usually going for a streamlined, clean look. In fact, for some professionals, such as members of the police or military services, keeping your shirt neat and tucked in is part of the uniform. Blousing occurs when the excess material that is tucked in around the waist pulls up and puffs out. With a little extra foresight and a little extra practice, you can keep your shirt from blousing.
Use care when tucking in your shirt in the first place. Make a fold on each side of your waist toward your back with excess material and hold them in place with your elbows. Keeping the folds in place, secure your pants around your waist.
Put on a belt that fits firmly around your waist. Do not tighten the belt so much that it is uncomfortable, but make sure it is effective in keeping your shirt in place where you tucked it.
Practice using good posture. Shirts often blouse when the wearer leans or slumps forward or bends over at the waist. You can help keep your shirt tucked in by sitting up straight and bending at the knees when you need to pick something up.
Purchase a pair of shirt stays, which are like reverse suspenders that fasten at the bottom of your shirt under your pants and hook onto the top of your socks to keep your shirt nice and tight.
Shirts that are to be tucked in should have an extra 6 inches from the waist down. When you are purchasing a shirt, tuck it in and raise your arms over your head to see if it stays in place.