I came up with the idea because some good American fishinglures are to big or to heavy to fish with in the Netherlands When fishing on Dutch Pike.
The water is often very small and shallow.
Press the lure half in the clay and make the clay as smooth as possible.
It's important that the clay is pressed around the lure and leave no spaces.
Make a couple of holes of 1/4 inch. This make it easier to match the two parts of the mold later on.
For example, you can do this with the back of a pencil.