First, you need to know the Team Fortress 2 universe well. Study the characters, their personalities, and the overall lore. For your female OC, give her a unique backstory. Maybe she's from a different part of the world that has a connection to the game's setting. For example, if there's a war - torn area in the TF2 lore, she could be a survivor from there.
One great 'female OC x Team Fortress 2 fanfic' is 'The New Recruit'. It has a well - developed female original character who joins the Team Fortress 2 crew. The story focuses on her adjusting to the chaotic world of the game's universe. It has great character interactions and a really engaging plot.
Well, Spy x Family fanfiction can be really interesting. Some fanfictions might explore different relationships between the characters in more depth. For example, they could focus on the bond between Anya and Loid in a new situation that wasn't shown in the original manga or anime. It's also fun to see how authors play with the spy and assassin themes in unique ways.
Spy x Family manga has wrapped up. It provided a conclusive and fulfilling storyline that wrapped up all the loose ends. Now you can binge-read the entire series without any interruptions.