How do you add models in Roblox

Well, the main way is to:

1. Simply group the bricks together that you want to make a model out of (after you have made it, of course). You can do this by: 1. dragging your mouse around the bricks, and once they are all selected, group them (Ctrl+G), or 2. (safer) hold down the shift key and click every brick you want in your model and then group them (Ctrl+G). This is better because simply dragging your mouse may select a few unlocked bricks that are unwanted (Baseplate, Invisible brick, etc...).
2. Make sure that ALL scripts that concern the item are placed under it's name, "Model", under the "Roblox Explorer" page, in the "Workspace" file.
3. Select the object.
4. Go up to file>publish_to_roblox...
5. Select the name of your model and description.
6. Select the amount of money it is worth, or if not, select the "Free Model" button.

Whalah! you have a model! You can sell these on Roblox's Catalog, or simply just save them into the free models folder for later use!