I was on my way to bed, but logged back in to post. It's all about taste in my mind 
Trial and error 
For instance, I prefer something sharp and 'vinegary' to hit my palate, whereas someone else will like something to slip down easily Go to a good wine seller and they should be able to guide you, as per the grading on the bottle. Even if you don't buy from them you'll get an idea as to what you need to look for in a supermarket