The self-referencing interferometer (SRI) is an innovative wavefront sensor (WFS) developed specifically for applications requiring laser propagation in strong scintillation. The performance of conventional gradient sensors, like Shack-Hartmann WFSs or lateral shearing interferometers, are severely limited in these environments due to the presence of branch points in the wavefront phase. In comparison, the SRI WFS directly measures the wavefront field so its performance is not affected by the presence of branch points. Over the last two years the Starfire Optical Range has been developing a prototype SRI WFS to demonstrate its advantages in strong scintillation environments. This paper discusses some practical lessons learned in building and operating an SRI WFS and presents initial results from laboratory tests.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.