This work reviews the key aspects on the design and analysis of fibre-polarization control components based on liquid crystal (LC)-infiltrated photonic crystal fibres (PCFs). The physics governing the electro-optic actuation of LC materials both inside cylindrical capillaries and the entire PCF lattice are discussed. Different light guidance mechanisms in LC-PCFs are investigated in detail for various combinations of fibre geometry and materials. Finally, three all-in-fibre LC-PCF switching elements are rigorously investigated: a single-polarization switch, a complete polarization controller and a polarization splitter.