Open Roblox Studio
Create or choose a shirt, pants, or T-shirt template
Download the official Roblox clothing template
Edit the template in an image editor
Add your design to the template
Save the image as a PNG
Go to the Roblox website
Open the Create page
Upload the clothing item
Name the item
Pay the required upload fee if needed
Wait for moderation approval
Wear or sell the clothing after it is approved