The Call

At the start of a campaign, run each character's origin story. Grab their level 1 sheets, and reverse a child out of it. Run a short few encounters that explain how/why they became this person.

Did their god reach out and shelter them in a time of need, earning their faith and devotion? Did they feel a swell of pride when protecting someone, leading them to become a guardian? Did they fail when they most needed to succeed, and take up with dark powers regardless of the cost? Did they harbor a secret desire to share their genius with the world but have to shelter it from their judgmental family until they just couldn't anymore? 

 Take into account their background. Criminals might be part of a guild or gang. Acolytes would find their way to the church. Folk heroes go out folk heroing, etc.

It's more work, but should make it worth it.