Does anyone have a good recipe for Interferometry and Unwrapping processing using TerraSAR-X data?
lots of 
(you just have to search)
http://forum.step.esa.int/t/how-to-use-terrasar-data-to-creat-dem/5283/29
http://forum.step.esa.int/t/subsidence-map-in-3d-view/3135
http://forum.step.esa.int/t/regarding-coregistration-of-multipass-tsx-tdx-dataset-urgent-and-important/984
http://forum.step.esa.int/t/snaphu-unwrapping/341
http://forum.step.esa.int/t/dinsar-interferogram/60
Generally, the interfeometry section should clear many of your answers:
http://forum.step.esa.int/c/s1tbx/interferometry?order=views
There are tutorials as well:
http://step.esa.int/main/doc/tutorials/sentinel-1-toolbox-tutorials/