Dress Preview Toolkit

Design Toolkit

Dummy

Controls

Shirt Selection

50%
6%
0.50

Trouser Selection

50%
40%
0.50
Best practice: create each shirt and trouser on the same canvas size as the dummy image. Your current dummy and shirt are already on the same canvas size, but the shirt artwork itself is larger than the dummy body. That is why it does not fit automatically.
Later, when you design exact-matching clothes, you can keep the scale at 1.00 and the position at 50% / 0%, and the dress will fit much more naturally.