Crushing the substance to a powder increases the surface area of the substance, which allows more of the solvent to come into contact with the substance and dissolve it. Agitation helps to break up any clumps of the substance and allows the solvent to circulate more freely, which also increases the rate of dissolution. Raising the temperature of the solvent increases the kinetic energy of the solvent molecules, which allows them to move more quickly and break up the substance more easily.