This looks like fun!

A good way to "recruit" is to press-gang crew from ships the pirates raid. Some crew decide the life of a sailor has no excitement for them, so they'll offer to become pirates, as long as they get to play-act in front of the ship's officers that they were 'forced' to join.

the problem is, of course, most pirate ships have a lot of ordinary sailor-types, so look for people with skills, like navigation, gunnery, etc. These guys typically must be forced to sign the articles.