How do you get your bartender to work faster on goodgame disco without using any diamands?

To get your bartender to work faster in Goodgame Disco without using diamonds, focus on upgrading your bar and unlocking new items to increase efficiency. Ensure you have enough staff and resources to handle customer demands effectively. Additionally, completing quests and participating in events can provide boosts to productivity and help speed up service. Regularly check and optimize your layout for better workflow.