Simple rule is don't fly below LSALT in IMC, if you do it enough and get away with it you will eventually meet the golden bee bee.
DIY approaches - quick way to get yourself splattered over the rocks.
I am very qualified to speak on this issue having spent most of my flying career in the highlands of PNG. I have lost some good mates in CFIT accidents, and I am absolutely sick of hearing about these stupid wasteful accidents.
It's pilot discipline that prevents these accidents - the buck stops with the Captain. If the Captain hasn't got enough guts to stand up and make the correct decision, he or she shouldn't be flying....
Forget the rules, this stuff is what you must do to survive.