A fanfiction could focus on Mike's life at school. For instance, he could start a club related to his interests, like a martial arts or a detective club. And he meets a new student who has a connection to the 'A' mystery in some way. They team up to figure things out, and along the way, they develop a deep friendship or even a romantic relationship.
One interesting Mike Montgomery fanfiction could be about his relationship with the main characters in a different light. For example, a story where he becomes more involved in solving the mysteries alongside the girls. Maybe he has some hidden skills or knowledge that helps them out in a way that wasn't shown in the original series.
Yes, there are various love stories involving different characters in 'Pretty Little Liars' and Mike Montgomery is one of the characters who has his own relationship storylines.
Another plot could be Mike developing a relationship with one of the new characters in town. This new relationship could be complicated by the secrets and drama that always seem to surround Rosewood. For example, the new character could be related to one of the 'A' suspects, and Mike has to figure out if he can trust them.
You can start by looking on fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfictions from various fandoms, including Pretty Little Liars. Just search for 'Mike Montgomery' in the search bar, and you'll likely find a bunch of relevant stories.
A plot could involve Hanna and Mike starting a school project together and during the process, they discover a hidden connection between their families. This connection could be related to the events in Pretty Little Liars, like a shared secret from their parents' past.
Caleb Rivers is another character. In fanfiction, Mike and Caleb could become friends and work together on a project related to technology. Since Caleb is good with computers, he could teach Mike some new skills. And this friendship could also be a way for Mike to get closer to Hanna, which could create some interesting storylines and dynamics among the characters.
One idea could be exploring the backstories of the minor characters in more detail. For example, what was the life of Jenna before she became blind? Another idea is to create an alternate universe where the 'A' mystery was solved much earlier, and how the characters' lives would be different. Maybe they would all be closer friends and focus more on normal high school stuff like prom and college applications.
In some fanfictions, Mike and Hanna might have a really sweet friendship moment. For example, Mike could be there for Hanna when she's having a tough time with the 'A' drama. He might offer her some practical advice or just be a listening ear. It shows a different side of their relationship outside of the main plot of the show.
Well, a great plot could be that Caleb finds a strange encrypted file on his computer that seems to lead to a hidden treasure in Rosewood. As he tries to decipher it, he has to team up with some unexpected characters from the show. Maybe he also has a vision or a strange dream that leads him to believe there's something supernatural going on in the town related to the file. Also, he could get into a situation where he has to choose between his loyalty to his friends and his own personal gain from the treasure.
One idea could be to create a scene where the characters discover a hidden room in one of the houses in Rosewood. Maybe it contains secrets about 'A' or the past of the town.