Most people masturbate because obviously they want sexual release. Tantra in its more modern bastardized version  serves to delay sexual gratification for the purpose of having sex longer or for a male to be able to cum with out ejaculation. Tantric masturbation uses breathing and stroke techniques to edge yourself to achieve a more satisfying orgasm. This is also a way to train yourself to be able to last longer and please your lover. Getting comfortable in your own skin and being able to understand what pleasures you in turn naturally makes you a more patient and considerate lover. Many people get hung up on or feel great anxiety around sex, especially men because their is an implicit pressure to perform. Tantric masturbation offers an invitation to self  sexploration. There are quite a few books out there and if you need to put a little joy in your JOI, Goddess is here if you have an questions.