How did Scrooge's old employer celebrate Christmas in A Christmas Carol?

Scrooges old employer Fezziwig
celebrated Christmas by throwing a party for his employees.

When the ghost of Christmas Past shows Scrooge where he was apprenticed, the visit
generates strong emotions in Scrooge.  By this point he is already softened by having seen his
childhood self.  When he sees where he was apprenticed, his first job, he is deeply affected by
the mans generosity.

Scrooges employer Fezziwig seems to have been a kind and
generous man.  Every Christmas he threw a party for his employers, with his entire family
attending.  It had plenty of good food, a fiddle player, and dancing.  Everyone, including young
Scrooge, had a great time.

When the ghost asks Scrooge why Fezziwig deserves
praise when he clearly spent only a few pounds of money, Scrooge explains that Fezziwig had
power over them as an employer, and spending the time to give them a party was what was
valuable.

He has the power to render us happy or
unhappy; to make our service light or burdensome; a pleasure or a toil. €¦ The happiness he
gives is quite as great as if it cost a fortune. (Stave 2)

The reason that Scrooge and the others enjoyed the party was because they appreciated
the fact that it was Fezziwig that gave it.  He gave them time out of their work day to
celebrate the holiday with them.  He treated them like family.  These are the things that made
the party valuable, not how much money he spent.

When Scrooge sees this
vision from his past, it makes him reflect on his present.

Something, I think? the Ghost insisted.

No, said Scrooge, No.
I should like to be able to say a word or two to my clerk just now! That's all. (Stave
2)

Seeing the enjoyment and camaraderie that he
experienced with his old employer and master makes Scrooge appreciate the role he plays in Bob
Cratchits life.  Scrooge has not been treating Bob very well, and he realizes this.  It makes
him want to treat Cratchit better.

Scrooge keeps his promise.  One of the
first things that he does when he wakes up on Christmas morning is send the Cratchit family a
giant turkeywithout telling them who it is from.  Then when he sees Cratchit the next day, he
promises to help his family and take more of an interest in his life.  He realizes that Fezziwig
was a role model for him.  He wants to live up to his example.