I have some back of the envelope guidelines for theta/vega and delta/vega. I don't use any ratios involving gamma. I mitigate gamma by exiting trades several days before expiration since gamma intensifies the closer an option gets to expiration. I have written extensively about this, but I'm tired of getting pounced on by the trolls. Feel free to message me if you would like to discuss.
I am not trying to be obscure, but I cannot really elaborate for a number of reasons. You can get there pretty quickly from what I have stated.
Bobby I would not jump in here, these are discussions on complex trading books and using greeks in a way to measure risk. You are just selling naked strangles and the market has not been that volatile like 2008-2009 where vols exploded. Even Trump election saw wild swings but no real vol jump like from 15 to 40. 2016 has been real quiet with respect to index vols if you look at a chart.
You are right. I manage my portfolio almost exclusively by the Greeks and their relationships to one another. No need to share something that works.