more details about the thickness of plastic part
before deciding a certain thickness, you need to balance something like economics, and part quality and strength, these contain the material type, part size, and molding conditions and so on.
understand product well
As a professional mold designer, it is very important to understand product well. For example, where and how is the product to be used? Required fits with other products, finish, strength, location of gate, ejector, etc.