indiePub has publish4ed an article by Celso Riva of Winter Wolves about making (and selling) dating sims and visual novels.
From the article:
"For dating sims, the best way is to split the story into scenes. Those games usually have several characters that you can date and, through gameplay, you advance every subplot scene by scene...
Those games are also famous for having many endings. In fact, the more the better because it is normal to replay a game several times to unlock them all. It's a lot like achievements in other genres."