Always taste your beer as your working with it. For example you can get a good idea over time from past experience to how your beers conditioning also if there were flaws in the fermentation or if the yeast need more time to clean up fermentation by products.
Taste your starter samples too
It's your nose eyes and tastebuds your relying on as a brewer. Think a good cook will be tasting that soup as their making it to see if it needs more salt or herbs and spices they only know this from past experience tasting their soup.