When I think of Echeverias I think of higher altitude locations in the tropics. Rocky places with some degree of seasonal drought, or unpredictable rainfall. When we went to Puebla to chase after succulents, we had to climb the hill to get to the point where Echeverias started. They get summer rain there and it is uncomfortably warm but not flaming hot in the summer. Cool to cold but not a lot below freezing for very long at night in the winter.
I would think lots of light (and UV) is key in cultivation, lots of exposure to the breeze, stuff I can easily provide here without frying anyone. My failure rate with Echeverias is still a serious problem, but I think it has more to do with particular needs of particular plants (and my unwillingness to alter my usual standards of care to compensate). Seems they vary quite a bit in difficulty. I just move on to the next one and see how it goes.
