Btw, as mentioned many times, I fully agree that 80% of the results achieved is down to the beans chosen in the first place and the grind. This is my current mix (85% Brazilian Arabica, 15% Robusta). I've found that adding a small amount of the latter gives a deeper and more incisive flavour than is achieved with Arabica alone:
The grind itself (hand done) is slightly coarser than that normally used for espresso. I love the taste of this mix, but that won't stop me from still experimenting further!
The other thing I've learned is to completely ignore the 'old wives tale' about allowing a Moka pot to 'season' with remnants of old coffee, which is said to improve the flavour. Bollocks! It changes the flavour all right, but NOT in a good way, simply adding bitterness.
Therefore, after each use, I clean every part of the Moka pot thoroughly in warm water, especially those in direct contact with the coffee I'm going to drink. Then dry everything thoroughly.
The crucial parts here are the insides of the coffee chamber and the filter and gasket/spouts. Only when those are clean, and not caked with oily deposits of old coffee, does the coffee produced taste best! I also grind only as many beans as I need (measured) to make a large cup of cappuccino, fresh every morning, in order to maximise flavour.
Marco.