Open Roblox and go to your Avatar editor
Select the body type or scaling options
Lower the Width slider if available
Lower the Height slider if desired
Reduce the Body Proportions setting if available
Choose slimmer clothing styles
Use narrow accessories instead of bulky ones
Pick a thin body package if your account has them
Save your avatar changes
If using a classic avatar, choose a slim-looking torso and limbs
Avoid oversized jackets, backpacks, and layered clothing