In the previous chapters, we explained how to run VMC and DMC simulations using the “well-matured dough \(\Psi _\alpha \left (\mathbf {R}\right )\) prepared by the master.” This dough \(\Psi _\alpha \left (\mathbf {R}\right )\) had been sufficiently “matured” before baking, ensuring that “when subjected to QMC calculations, it yields a proper product.” Now, how exactly is this dough prepared? The fundamental procedure is as follows: In this chapter, we will go through this process through practical exercises, deepening our understanding of VMC.