I'm planning a story where three brothers hate each other, and I need to show the reason for this at some point. But the events that made them hate each other are prior to where the story actually begins, so I'm wondering how to present the reader with important information about their past, and the most obvious way seems to be flashback scenes. But I'm not sure if this is the best option, nor do I know exactly how I should do these scenes. It seems to me that simply cutting the story out of nowhere and, boom... *flashback scene* is an even lazier way than normal flashbacks. How exactly should I set the stage for such a scene? And what other less obvious ways would be good for showing the characters' past?
By the way, this is my first story.