Take a small section of the front hem, tuck it into your waistband, then gently pull a little fabric back out. Leave the sides and back loose. Start small and adjust the amount until it feels comfortable.
Begin with the waistband
Put on the bottoms you want to wear and let your tee fall naturally. Choose a small section near the center front rather than gathering the whole hem. A soft oversized tee gives you room to experiment.
Keep the tuck easy
Push that small section just inside the waistband. Then lift your arms and let the shirt settle before pulling out a little fabric. A loose fold looks relaxed and gives you room to move.
Try an off-center version
Move the tucked section a little to one side for a different line. You can leave more fabric loose on the other side. A mirror photo can help you see the overall shape, but the best version is the one that feels comfortable throughout your day.
Finish with one clear contrast
Try a roomy black tee with lighter denim, or a charcoal tank under an open white shirt. Repeating one color in your shoes or bag is an easy way to tie the pieces together.