A scenario could be that Lily travels back to her Hogwarts days and tries to change the way she treated Snape. This could have a huge impact on Snape's future actions and loyalties. Maybe she could have been more understanding of his difficult situation, which might have led to him not being so easily swayed by the Dark Arts.
In some fanfictions, Lily might time - travel during the Triwizard Tournament. She could appear to Harry and give him some hints or warnings. Since she has knowledge of the future and the danger that Voldemort poses, she could be a mysterious figure guiding Harry through this difficult time, adding a whole new layer of mystery and intrigue to the story.
Lily could time - travel to the moment when Voldemort was about to attack her family. Instead of just sacrificing herself, she could use some sort of time - magic to trap Voldemort in a time loop, preventing him from ever harming her family or the wizarding world. This would be a very creative and powerful take on the story.
One interesting plot could be Lily traveling back in time to prevent James and Sirius from playing a particularly dangerous prank that had unforeseen consequences. Another might be Harry traveling back to meet his mother as a young witch and getting to know her in a whole new way. And perhaps Lily and Harry traveling back together to change certain events that led to the rise of Voldemort, like preventing the first opening of the Chamber of Secrets.
One interesting scenario could be their first meeting in a magical forest. The forest is filled with glittering fireflies and strange, beautiful plants. James might be a bit clumsy and say something silly at first, but Lily finds it endearing. They start to talk about their dreams for the wizarding world, and there's an instant connection between them.
One interesting scenario could be that the kiss happens right after James has finally proven himself to Lily. Maybe he has just saved her from some sort of danger, like a dark wizard attack at Hogwarts. Lily, seeing James in a new light, is so overcome with gratitude and a newfound attraction that she impulsively kisses him. This would be a moment of realization for both of them, as James has been longing for Lily's affection for so long.
There are fanfictions that imagine Lily's life if she had survived. In these stories, she would be a key figure in Harry's life, guiding him and protecting him in ways that Dumbledore or others couldn't. She might also play a role in the wizarding world's politics, using her intelligence and magical abilities to bring about positive change.
There's a fanfiction where James and Lily time travel to the future. They are shocked by how the wizarding world has changed. They see new spells and magical devices, and they have to adapt quickly. They also meet their descendants and learn about their family's legacy in a whole new way.
Another interesting plot could be that they are sent forward in time instead. They have to adapt to the future wizarding world which has changed a great deal. They might be shocked by new magic technologies and different social structures, and their reactions to these changes can make for an engaging story.
One common theme is the exploration of family bonds. Since Harry never really got to know his mother, time travel allows for a deep exploration of their relationship. Another theme is the alteration of the past and its consequences. Writers often play with the idea of how small changes in the past due to Harry and Lily's interaction can have a big impact on the future of the wizarding world.
One popular 'Harry Potter x Lily Evans time travel fanfiction' is 'Back to the Start'. It has an interesting plot where Harry somehow travels back in time and gets to interact with his mother Lily Evans in a whole new way. The story does a great job of exploring their relationship and how Harry's knowledge of the future impacts the past.
One interesting fanfiction could be 'The Unseen Bond'. It delves into an alternate universe where Harry and Lily have a unique connection that transcends time. It might explore how their relationship could have developed if Lily had not died. Another one could be 'Lily's Return', where Lily somehow comes back to life and her relationship with Harry unfolds in a very different Hogwarts setting, full of mystery and new magical adventures.
One interesting plotline could be a story where Lily survives Voldemort's attack. In this scenario, she has to deal with the aftermath and also raise Harry in a very different wizarding world. Her relationship with Harry would be more of a traditional mother - son relationship, but with the added complexity of the wizarding world's politics and the threat of Voldemort still looming. This would allow for a lot of character development for both of them.