In Holy Rummy, keeping an eye on the cards that other players have discarded is crucial because it can reveal important information about the cards that you can use to finish your sets and casino game appruns. Also, you can significantly increase your chances of success by effectively managing your hand and understanding when to discard or hold onto particular cards. There are other game variations as well, like "Gin Rummy," which have their own special rules and tactics. To succeed in Holy Rummy, one must possess a combination of skill, strategy, and a small amount of luck.