Why would you want to improve them? This is exactly how they're supposed to be.
There's an allegorical painting in the Taoist tradition with Buddha, Confucius, and Lao Tze each tasting vinegar. Buddha looks like he's in pain after tasting it because life is suffering. Confucius is angry because it's not pleasing. Lao Tze is smiling because vinegar is supposed to taste like that and he appreciates it for what it is.
This photo is vinegar.