Open Roblox Studio
Create or open a place
Design the item model
Add parts, meshes, or accessories
Group the item into a single model
Name the model clearly
Set the model’s PrimaryPart if needed
Add scripts for item behavior
Test the item in Play mode
Save the place
Publish the item to Roblox if needed
Create a thumbnail or icon
Set item permissions and ownership
Use the item in a game or sell it through the Marketplace