At the core of neuroaffirming practice is a deceptively simple idea: that effective clinical practice starts with the individual. Not just understanding what someone is experiencing, but how, why, and in what context. Yet our clinical trials and research methods rely on standardised interventions that obscure individual processes. Leaving clinicians to make evidence-based decisions for autistic from results derived in non-autistic populations, or from group averages that assume uniformity rather than reflect heterogeneity. In this address, I will make the case for building neuroaffirming clinical evidence from the ground up, research that starts with autistic experience rather than retrofitting frameworks developed in and for non-autistic populations. I will present findings from a program of work that spans surveys, daily diary methods, idionomic modelling, and experimental designs, examining processes central to psychological wellbeing including sleep, identity, stigma, and psychological flexibility. Across these studies, I will demonstrate how the same process can operate differently within individuals, across time, and across subgroups and what this means for both science and the clinic. These findings have direct implications for how we assess, formulate, and support autistic clients. I will discuss how process-based research can move us beyond one-size-fits-all assumptions toward more personalised and affirming care. The goal is not just better science, but evidence that is built to serve the people it is meant to help.