Fluorescence polarization is widely used to assess orientation of molecules, their rotation and excitation energy transfer processes between closely located chromophores. Emerging single molecule fluorescence spectroscopy and imaging since the 1990-s stimulated application of light polarization for studying molecular organization and energy transfer beyond ensemble averaging. Here we present an overview of traditional fluorescence polarization and linear dichroism methods used for bulk samples and compare them with techniques specially developed for or inspired by single molecule fluorescence detection. In particular we will focus on the possibilities of assessing energy transfer in anisotropic samples where the traditional fluorescence anisotropy philosophy is not readily applicable, and present the concept of single funnel approximation, which was developed in this context. We will show examples ranging from addressing fundamental properties of conjugated polymers, light-harvesting aggregates, perovskite semiconductors to bio-medical imaging. Strategies for avoiding artifacts in polarization measurements will be also discussed