This article describes the experiences of two Internet startup companies adopting effective and efficient modeling and documentation practices. Both organizations successfully developed agile approaches for enterprise architectural modeling, one taking a communal team-based approach and the other a chief architect approach. They adopted similar strategies for project-level modeling, adopting highly iterative and incremental approaches that focused on the act of modeling and not on the resulting models themselves. There is a "sweet spot" where modeling efforts can provide significant benefit without incurring the costs of onerous documentation.