Novel methodology developments and applications of a variety of spectroscopic and spatially resolved NMR experiments are presented here. NMR has poor sensitivity, especially for rare spins. We have developed novel relaxation optimized double quantum filtered transition selective experiments to improve the sensitivity of rare spin correlation spectroscopy: Low Abundance Single transition correlation SpectroscopY (LASSY) in direct detection mode and 1H Indirect detected Carbon Low Abundance Single transition correlation Spectroscopy (HICLASS) in the indirect detection mode. These approaches typically halve the measurement time to produce a given sensitivity, in comparison to INADEQUATE CR and ADEQUATE respectively. They may be applied to 13C, 29Si, Sn isotopes, 183W, 77Se, etc. Secondly, the time evolution of multiple quantum coherences under spin lock has been studied in spin-1/2 A2X2 systems, and is shown to result in ‘amplified’ homonuclear scalar couplings. Further, the utility of...