Precision microscale gyroscopes have been gaining much attention for a wide range of applications. Micro-electromechanical System (MEMS) gyroscopes have the inherent advantage of small size, weight, power, cost (SWaP-C), and can be easily integrated on chip. However, the performance of commercial MEMS gyroscopes is still limited and requires further improvement to meet the requirement for high-end applications such as inertial navigation or dead reckoning. High quality factor (Q) resonant gyroscopes are proven to achieve higher performance through the Q amplification principle. The mode-matched operation requires frequency and mode control to compensate for the imperfection from MEMS fabrication process. Over the past decades, the frequency and mode control of MEMS resonant gyroscopes were mostly achieved via electrostatic spring softening, using narrow parallel capacitive gaps. However, some newly developed MEMS gyroscopes in more recent years require alternative methods to achieved frequency and mode control. For example, in a capacitive gyroscope, with a wide transduction gap, the tuning can be severely limited, and furthermore piezoelectrically transduced gyroscopes do not have such capacitive gap for tuning. The challenge in controlling the frequency and mode is a major hurdle in converting high performance MEMS resonators into a precision gyroscope. This dissertation aims to provide a coherent study of precision frequency and mode control in MEMS gyroscopes, exploring both silicon and monocrystalline 4H-SiC substrates. It introduces a first-of-its-kind solid disk capacitive BAW gyroscope using 4H-SiC, which demonstrates high quality factor and minimal mode mismatch due to its unique structural properties. Additionally, the research develops a mechanical trimming algorithm for mode-matching, showcased in an AlN on silicon BAW gyroscope. This approach significantly reduces frequency splits caused by fabrication imperfections and enhances mode isolation. The study also introduces a novel multi-coefficient eigenmode operation, improving cross-mode isolation and reducing quadrature errors. This comprehensive research advances our understanding of frequency control and mode alignment in gyroscopes, offering new solutions for high-performance MEMS gyroscopes.