Alternating massage with more sensual play can build a delicious tease, so mix therapeutic moves with more erotic stroking. Try kneading the shoulder muscles before softly trailing your fingertips down the side of your lover's neck, or massaging the sides of the buttocks – which can store a lot of tension – then letting your fingers stray to more intimate zones. For a super-hot treat, try liberally covering your lover in lube then sliding your body over theirs (assuming you're not significantly heavier than them). And above all, communicate: ask your lover what they enjoy and do as they desire.
The more you know about the body, the more effective your massage will be, so study the basics of male or female erogenous zones, and general anatomy to help you best understand how to caress your lover. A little knowledge can reap a lot of rewards.