Your aim is to stop your phone conversation before that trough occurs. For your initial phone call to a man, allow 15-20 minutes. You may gradually expand the duration as you get to know each other better. If he seems interested, take his number and name and write it down so you don't forget it. During a phone conversation with a guy, there are several signs that it is time to end the call. If he doesn't offer any, find another topic of discussion. Also, pay attention to how long he talks without interruption. The more he listens, the more interest he shows in you. Finally, avoid calling him too late at night, because that will seem like a message instead of a call. Ending a phone conversation with a guy is easy - just make sure that you end it on a good note by saying something like "have a nice day," or "talk to you later." Don't worry about not getting his number - many people like being able to contact someone even after they've stopped talking to them. As long as you have had a conversation with a man and he has shown an interest in you, then you have ended a phone conversation with him.