Here we are explaining how to create mug in Solidworks software.
Link given below will show you how to create mould for externally threaded parts.
https://youtu.be/tb4oWtGxQpo
Link given below contains Plastic product design . I had tried to use simple english to understand plastic parts.
https://youtu.be/lOK1YkarKlo
To understand solidworks mold tools please see video in link given below
https://youtu.be/5JLFxiDuY2Q
Also see video to make mold for tea cup
https://youtu.be/iAAQPvkGHKU
Link given below shows how to create mould for bath mug without side core
https://youtu.be/n3I873Y6pt4