One of my teachers in Toronto, Walter Principe, C.S.B., had a long-standing interesting in St Thomas's "spirituality," worked on this topic, and published on it, until the very end of his life, in 1996.
Isn't life interesting? Another one of my other teachers, James Weisheipl, OP, wrote an article once insisting that St Thomas had no spirituality, to his credit!
Anyway, a nice overview of Fr Principe's thinking on Thomas's spirituality can be found on-line, on the Spirituality Today website. The article is entitled "Aquinas' Spirituality for Christ's Faithful Living in the World," Spirituality Today 44/2 (1992): 110-131 (link).