regarding PSI: Did you see this overview? About the STaMPS category
regarding DInSAR: Suggesting parameters for unknown study sites is quite hard. But if your results are not good enough you can check if you find pairs with
- better coherence
- less atmospheric disturbance
- better perpendicular baseline
See this PDF with some hints on suitable conditions: http://www.esa.int/esapub/tm/tm19/TM-19_ptB.pdf10
Chapters 1.3 and 1.4.1