Firstly you need to make a difference between the quality of a wine (which is objective) and the perception that you have (which is subjective.)
The determine objectivly the quality of a wine you have 3 main steps.
To begin, you need to check that the wine does’nt have any default. You can see it thanks to the color of the wine, the smell and the taste.
Secondly, the wine need to have a nice balance.
For the white wine, the balance has to be between the acidity and the smoothly ( sugar, alcool). For example if the white wine is too much acid, you will find the wine too much « green ». Conversely if the wine is too much « fat » (a lot of sugar and not enough acidity to balance with it) the taste will be disgusting.
For the red wine the balance has to be between acidity, oiliness and tanin.
Thirdly, the wine needs to stay a long time in the mooth.
Before swallow it, the more you keep in mouth the taste of wine, the best it is.