Put on the shirt and smooth out any wrinkles
Unbutton or unzip the bottom if needed
Tuck the front hem into your pants or skirt
Pull the sides evenly so the fabric lies flat
Tuck the back hem in as well
Adjust the shirt so it sits comfortably at the waist
Pull up your pants or skirt to hold the shirt in place
Smooth the shirt over the waistband
Check the mirror and fix any bunching
Re-tuck loose areas as needed