How to start a new D&D campaign

It always starts the same way. One night, a group of adventurers who have never met one another are in a tavern and they hear one of the following things:
A feared local monster has returned from a dark pit in the hills and is terrorising the locals.
A lost treasure, rumoured to be hidden in caves along the storm tossed coast has attracted generations of foolhardy explorers and its location is revealed to the players.
A local has been kidnapped by bandits in the swamps, and their leader has a weapon of strange and terrible power.
These comparative strangers then decide to form a band in order to right a wrong and go off on a quest.
But who actually would do that?
In this article, we're going to look at two things.
Firstly, how you the GM can work with players (and if players are reading this, how you players can work together), to create a great player group if you've never RPGed with one another before.