Do unto others...
As you damn well please, if you have diplomatic immunity

An eye for an eye...
Is a reasonably even trade-off. A pancreas for an eye, however... well, that becomes much more interesting.

If you can't beat 'em...
Cheat

If it ain't broke...
Some shithead will fuck it up sooner or later.

Give a man a fish and he'll eat for a day...
Give a man food stamps, and he'll eat junk food for a lifetime, at taxpayer expense.

Honesty is the best policy...
But lying can be remarkably practical and effective as well.

The grass is always greener...
Well, maybe not in California lately