JerDGold wrote:Just remember, only change one variable at a time, or else you won't know how you got where you ended up.
It may sound strange, but you're well advised to keep a notebook in which you record the results of each and every change you make. You'll never remember every combination, let alone what it produced in the cup. Even now (55 years into the hobby), I record the grinder setting, doses and other parameters for best results from the beans and blends I plan to use again.
I learned to do this when I took photography seriously back in high school. Without exposure values etc, there was no way to remember what went into a great print even a few weeks after I made it. And (as with espresso), it was even more important to know how I got bad results, so I didn't do it again.