For me, only one strategy works - not to see the faults of mother-in law and try to escape the conflict. How I do this? Well, I do this by getting inspired from the following post, which is in line with this one:

http://www.dadabhagwan.org/path-to-happiness/relationship/problems-in-relationship-stop-fault-finding/how-to-deal-with-mother-in-law-problems/