Single crystals are the repeating atomic arrays of atoms in three dimensions. It is clearly more difficult to grow single crystals and takes extra attention. This extra effort is justified because of their outstanding advantage over polycrystalline e.g. uniformity, anisotropy, and absence of grain boundaries. Without crystals, electronic industry, photonic industry and fiber optic communications would not be imagined and crystals are unacknowledged pillars of technology. Many physical properties of materials are complicated by the effect of grain boundaries and single crystals are necessarily needed to find actual physical properties. Particularly, our transport experiments for realizing surface states in topological insulators, visualizing quantum oscillations for establishing Fermiology etc require high quality single crystals. Depending on their physical properties, suitable growth route can be chosen: flux growth, self-flux growth, Bridgman, chemical vapor transport or optical floating zone.