I think you can tell if you are getting a kind of chemistry with someone before it leads to being asked out on a date most of the time. It can lead on to being better well aquainted and possibly another date or you may find that although you get on well it's not quite what you were looking for. Depends on whether it is a potential partner that you are after or a going out friend that you want. There is a difference.

In my youth many a blossoming friendship ended because of something as silly as disagreeing about certain tastes of music, friends or clothes which probably showed that I was too young to date anyone in the first place.