  In this lecture, we describe a number of advanced gain calibration
techniques. In particular, self-calibration is an important tool in
interferometric imaging at all wavelengths. It allows the observer to determine
and remove residual phase and amplitude errors that remain in the data after
normal calibration while simultaneously producing a more accurate and more
sensitive image of the target source. We describe the basic technique of
self-calibration and attempt to dispel some common misconceptions. We proceed
to give a range of useful tips, and provide continuum, spectral line, and
mosaic self-calibration examples using ALMA data. We also discuss fast
switching and radiometric phase correction along with advanced phase transfer
techniques that can become advantageous or even essential at high frequency
where the density of sufficiently bright phase calibrators becomes sparse.
