Lithium magnesium phosphate LiMgPO4 is one of the most promising materials for luminescence dosimetry. In this paper, we consider methods for the synthesis or additional processing of this material, such as microwave, hydrothermal, and flux techniques, as well as melting followed by quenching, which makes it possible to enhance its thermoluminescence by increasing the crystallinity of the samples and improving grain contacts. The best properties are shown by the LiMgPO4–Na2B4O7 composite.