We report on the design processes of two ongoing soma design projects: the Pelvic Chair and the Breathing Wings. These projects take a first-person, soma design approach, grounded in a holistic perspective of the mind and body (the soma). We contribute a reflective account of our soma design processes that deepens the field's understanding of how soma design is achieved through first-person approaches. We show how we use our somas, our first-person experiences, to stimulate a design process, to prototype through and to use as a way of critiquing emerging designs. Grounding our analysis in new materialism, we show how our designs are in essence, "performative intra-actions". Using our own somas, our designs open up for experiences within certain constraints, allowing for a material-discursive agency of sorts. Many different somas may be intra-acted through our designs, even if it was our somas who started them.