Sex therapy is a lot like other individual or couples therapy except that it focuses more directly on the sexual component: your feelings, your behaviors, your response, your difficulties and your fulfillment. Because I am also a psychotherapist and couples therapist, there may not always be a clear line between "regular" therapy and sex therapy. But you may have discovered that some therapists are not entirely comfortable or may feel out of their depth in frank and detailed discussion of these matters. My AASECT certification means that I am extensively trained, knowledgeable, and experienced discussing and helping clients in sexual matters.
Sex therapy is a conversational therapy. Therapy sessions involve no touching, nudity, or sexual contact. As in other therapy, I am likely to suggest activities and explorations for you to pursue outside of session, sometimes individually and sometimes with your partner. This homework may involve reading books or articles or watching videos, or sometimes just thinking and writing down your thoughts for later discussion, as well as the more physically intimate activities you might expect as homework.
Sexuality is about so much more than how Tab A fits into Slot B. As Yogi Berra once famously said about baseball, "[this game] is 90% mental and the other half is physical." When couples feel they're experiencing problems in sexuality, I often find that there is too much focus on the physical without enough understanding of the mental; or that one partner is focused on the physical while another is struggling with the mental. But it can also be the other way around; overthinking (or other factors) can interfere with being primally "in the moment" with your partner. My job is to help you find your way to a balance.
People trying to solve a problem often mistakenly believe they know where the problem lies and only need to try harder at doing what they're already doing. I find that is rarely the case. So the homework I assign tends not to be "more of the same, but try harder." Based on my insights and experience with other couples, some of the activities I assign may be things you wouldn't have expected or necessarily associated with your sexual experience.
But the overall goal is to increase your intimacy and improve your physical and emotional experience of sexuality, and you'll get plenty of opportunity to practice those things together, too (at home, of course).