A while back, I got into diagnosing how an espresso should taste by how it smells right after the bean is ground. Adjusting temperature and dose to achieve the taste that resembles the smells. I now look for coffees now that smells fabulous and then look to translate that into something similiar in taste. I find a symmetry between smells and tastes to be an ideal.
Yeah, it sounds obvious in retrospect. 'Good coffee should taste as good as it smells.' The turning point for me in really making this a quality judgement was this bag of Guatemala I tasted. Yeah, it was fine as drip but in espresso there was some funk to it. A Co2 gassy/bitter taste that was unpleasant. In espresso, it was unbalanced, muddled, and the funk came out at me. I realized just how intertwined the smells are to the espresso when I smelled the bag afterwards. The funk smell was there but I had not taken the time at every step to just smell the beans. At work, I had gotten to the point where one whiff can tell me the character of the bags. Light roasted nuts always means pleasant shots. I just had not yet put that into a forward movement. I knew what it tasted like when right and was evaluating the smell as it compared to the flavor I tasted.
Now, when I get a new espresso, I smell it. I smell it when I open the bag, when it's ground, before I sip the shot, and then I smell the puck.
So stop. Take the time to smell the coffee.