TESOL theory is intended to inform teacher practice, but studying what teachers actually do in a given teaching context can sometimes lead to better theory. This report illustrates an area in which practice informed theory in the context of 1-on1 writing conferences for prematriculated ESL writers. This report describes the creation and implementation of a writing conference program for 250 prematriculated students at an Intensive English Program (IEP) with language proficiencies ranging from high-beginning to low-advanced. The theory-driven philosophy of conferencing encouraged teachers to meet 1-on-1 with their writing students 5 times during a semester to provide holistic, nondirective, level-appropriate feedback on student writing and to de-emphasize grammar instruction in these interactions. While teachers largely followed this philosophical direction, they also made modifications that were not entirely expected. Specifically, teacher practice deviated from conferencing philosophy in terms of the purposes of conferences, the role of grammar feedback, and the use of reflective practices to shape classroom instruction. Confronting these unexpected areas of teacher practice to learn from them rather than remove them allowed the writing conference program to thrive. It also pointed to areas where the writing conference philosophy, and its theoretical underpinnings, could be reevaluated to become more descriptive and inclusive of actual practice. This report also provides insights other theorists and practitioners may find valuable in establishing their own writing conference programs.