The preparation of carbon nanomaterials has been the focus of many research groups over the last twenty years. Traditionally, the synthesis of these materials has been accomplished using physical methods involving harsh conditions, limiting their applicability in numerous technological areas. Thus, researchers have been constantly working on developing new methods involving organic molecules possessing highly reactive functional groups that can be graphitized under mild conditions. In this tutorial review, we highlight recent approaches for the preparation of various carbon nanomaterials using physical stimuli (heat and/or light) to trigger graphitization of both non-organized and self-assembled molecular precursors. Special attention is devoted to the preparation of carbon nanomaterials from alkyne-containing molecules.