Buy a spade. In the Guild, choose a new Quest and choose to Boast about it. You will be transported to the Boast Podium in Lookout Point. A group of people should flock to you and cheer. Step off the podium and find a diggable patch of ground. Now dig. Every time you dig, the characters in the area will be reloaded; as this is the only place in the game where human NPCs are randomly generated, the generation process will be repeated and more people will spawn. Continue doing this until you have a huge crowd of people, then pull out a Trophy and show it off to the amassed onlookers for huge amounts of Renown points.Additionally, killing masses of them at a time with magic will net you a large Combat Multiplier and a nice chunk of experience.Note: Your XBox may lag if there are too many NPCs on-screen at once; therefore, 100 is a good recommended upper limit of NPCs.