One common theme is self - discovery. Finn and Emma are both characters with their own insecurities and issues, and a lot of fanfictions explore how they grow and learn more about themselves through their relationship.
Love and acceptance is also a big theme. Given their different backgrounds and personalities in the show, fanfictions often deal with how they come to accept each other fully and fall in love. For example, Emma might struggle with her OCD while Finn has his own problems, but they learn to love each other despite these differences.
One common theme is friendship. Since Will is a teacher and Finn is a student, their relationship can be explored in terms of mentorship and friendship. Another theme could be their shared love for music within the Glee club setting.
Another common theme is self - discovery. Since both Will and Emma have their own personal growth arcs in the show, in fanfiction, they often continue to discover things about themselves while in their relationship. It could be about Emma learning to be more confident or Will realizing his true priorities in life.
Friendship is a very common theme. Writers often explore how Sam and Finn support each other, have each other's backs, and grow closer as friends. For example, in many fanfictions, they help each other deal with relationship problems.
One common theme is friendship development. Since they have different personalities in the show, fanfiction often focuses on how they overcome their differences to become friends. Another theme is support. They might support each other through things like auditions or dealing with mean classmates.
One common theme is redemption. Puck especially has a bit of a rough past in the show, and fanfiction often explores his journey towards redemption, with Finn sometimes playing a role in that. Also, the theme of family comes up. Given their different family situations, fanfiction might look at how they support or envy each other's family situations. There's also the theme of loyalty, as they are part of the Glee club and have to be loyal to their friends there, which includes each other.
One common theme is friendship. Quinn and Finn have a complex relationship on the show, and in fanfiction, it's often explored in terms of a deepening friendship. Another theme is self - discovery. They both go through a lot of personal growth in the series, and fanfiction continues this journey, like how Finn discovers his true passion outside of football or Quinn finding her place outside of the Cheerios.
One common theme is friendship. Since they are both part of the Glee club, stories often explore how they become closer friends or how they support each other through different challenges in the club. For example, they might help each other with song selections for competitions.
One common theme could be the exploration of unexpected parenthood. Since it's mpreg, it's a very different take on having a child. Another theme might be the relationship between Puck and Finn, how they deal with this new situation together or separately.
One common theme is guilt. Finn usually feels guilty about his actions, which can lead to a lot of internal conflict. Another theme is forgiveness. Whether Rachel forgives Finn or not can be a big part of the story. Also, the theme of trust being broken is often explored.
One common theme is their relationship development. Fans often write about how they fall in love, overcome obstacles in their relationship.