Coffee Appreciation

Assuming you've got a grinder which does an acceptable espresso grind; filtered water and that's it. I wouldn't take it any further. I'd argue you don't really need the shower screen or VST basket. I've never bothered but people do say it makes a noticeable difference.

Some accessories which come in handy are a blind basket and Puly Caff tabs for backflushing, and a pressure gauge for checking the pressure when you do the spring mod. There are plenty of pressure gauges out there with the thread which goes into the bottom of your portafilter.

A dosing cup and a bottomless portafilter helps, but they aren't must haves.

PID to replace the bimetallic thermostat was the lightbulb for me in terms of consistency!