Here is my take on all that I have read on dialing in my Baratza Preciso grinder for a shot of espresso:
Weigh beans to start with 14g freshly roasted beans for a double shot.
Start using 10.5 on the macro setting, and the micro setting in the middle of the range.
Grind a few tablespoons of beans through the machine to start off so the ledges in the machine that capture a bit of grounds will be full for following grinds.
After leveling and tamping the basket in the portafilter, pull a shot through the Faema Faemina and time the extraction.
Adjust the grind coarser if the extraction takes more than 30 seconds, and finer if less than 30 seconds.
At this point I will not care if the group overheats because I am just determining the correct grind. After I find it, I'll allow the group head to cool off before I pull a shot to refine my extraction process for taste.

Sound about right?

All looks good to me. A couple things I learned when getting mine dialed in.

-Small adjustments
-Use a bottomless portafilter (this will allow you to see channeling and uneven extractions causing changes in your shot time.)
-Get to your target faster by feeling the grind to be slightly smaller than a grain of sand.
-Tamp the same each time. duh! I know