What is a mold?
A mold is a hollow encasement that when filled produces a desired shape.
That's the easy question.
How do I make a mold?
Believe it or not, there is no wrong answer to that question. The answer depends on many variables. You have to consider the part, where to put the mold break line, orientation, sprues if used, are you doing multiple pours, can part be easily removed from the mold, how many are you making and many other possibilities.
I have made a 4 piece mold. As long as its tight fitting, make 6 or 7 piece molds if need be. Don't be afraid to get creative. There is no wrong way to make a mold. If it works...you did it right regardless of how you did it.
However there are some methods for making basic molds that really an make life simple.
Its time we reviewed and updated Garage Kit Casting.