Many do this by reading self-help books and articles, attending seminars, going to counseling, observing other successful couples, or simply using trial and error.
It can be a form of courtship that consists of social activities done by the couple.
These people will have dates on a regular basis, and they may or may not be having sexual relations.
This period of courtship is sometimes seen as a precursor to engagement or marriage.
The ones who were smart enough to just date got out unscathed.
At present I have a close friend that is finally cohabitating with his GF of 17 years.