How can a saturated solution be prepared?

Hint: A saturated solution or vapor is one which contains the greatest possible concentration of a dissolved or vaporized substance under given conditions of temperature, pressure and volume while still being stable. It is possible to get concentrations higher than what is found in a saturated solution or vapor but those solutions or vapors won’t be stable in nature.

Complete step-by-step answer:To form a saturated solution the primary requirements are the presence of a solute and a solvent, there are various factors that affect solubility of solute in a solvent and they must be kept in mind if we plan to prepare a saturated solution these factors are:
$\left( 1 \right)$Temperature- As we increase the temperature of the solution the equilibrium between solute and solvent is shifted forward making it possible for the solution to its solute content and thus become more and more saturated.
$\left( 2 \right)$Pressure- With enhancement of pressure applied on a solution we can indeed make more and more solute soluble into the solution thus making it more saturated.
$\left( 3 \right)$Nature of Solute and Solvent: Sometimes the compatibility of the nature of solute and solvent can affect the amount of the solute required to make a saturated solution, for example Sugar is more soluble in water than compared to salt.
Thus keeping all this in mind to make a saturated liquid solution we must keep undissolved solute in contact with the liquid solution. In case of solution in vapor phase we must keep unmixed gases in contact with the solid or liquid with which it is in equilibrium so as to form a saturated vapor.
Now, if we want to form a saturated solution at the earliest the best way to do so is to choose such solute-solvent pairs which are least soluble in each other, lower the temperature, reduce the pressure.

Note: While making a saturated solution we must always keep in mind factors like temperature, pressure and presence of impurities as this would help us in preparing a solution which reaches saturation whenever we wish to make it to.