Warm up the cup and filter by running some heated water through an empty filter into the cup and discarding it.  Fill and tamp the filter.  Then, wipe any stray grains of coffee off the top of the filter before placing it under the group head and tightening it.

When the proper temperature is achieved, raise the handle to the “up” position.  Count 10 seconds to allow water to fill the brewing chamber and pre-infusing the coffee before pulling down on the handle.  Likely, there is some rich dark espresso dripping into your demitasse and covering the bottom by this point.  Although I didn’t expect it, the pressure required to pull the handle down is quite hard.  I haven’t measured this yet, but it feels almost as hard as the pressure required for tamping.   Don’t force the handle down, but rather press down with CONSTANT heavy pressure.  The espresso should be thick and start flowing straight down in a heavy stream from the spout, and you should see crema forming.  The whole process from start to finish should take around 20-30 seconds.

A variation on this is to partly lift the handle (but not to the top, or you’ll have water flooding your work area!) BEFORE putting your filter in. I got this idea from one of the readers here. The theory is that lifting the handle sucks air through the coffee you worked so hard to tamp. This supposedly breaks up the coffee puck and messes up your pull. I’ve tried this, and it seems to work. Play around with this yourself and see if you get better results!