This is probably a simple answer,
I am cloning a hat onto the player's character. It works well; It sticks to the player's head. However, it clones onto the player both upside-down and backwards. I don't see any rotation features within the hat, only position. How can I rotate a hat?
Orientation!
Orientation is a property of all BaseParts and MeshParts. (Depending on what your using, you should give us some more detail!)
Orientation can be assigned to using Vector3.
To set the orientation you can do the following:
Part.Orientation = Vector3.new(y, x, z)
Additionally, if you are using Welds to "glue" the hat to the player, this may not work, and you may need to look in to using the offsets of the welds.
Links for stuff you might need: