My only advice here is patience. I went through a similar learning curve on my previous machine and turned to the naked. Then it reached the stage where I didnt seem to be progressing.
Theres an on-line resource here that might help but the clincher for me was
- ensuring that the basket was properly dosed (i was under-dosing)
- ensuring there are no gaps around the edges (especially where the handle meets the filter holder)
- and the tamp was level.
I have a Pullman which makes that a bit easier for a level tamp but if you have a ridged basket, that will give a pretty good indication of a level tamp.