One great 'loid forger fanfic' could be one where Loid has to navigate a complex mission that involves protecting Anya in a very public and dangerous situation. Maybe he has to use his spy skills in a way that doesn't arouse suspicion among the civilians while still keeping Anya safe.
First, study the character of Loid Forger. Know his traits like his calmness under pressure, his intelligence, and his love for his 'family' in his own spy - like way. Then, come up with an interesting plot. It could be something related to his spy work, or something more domestic within the Forger family.
Definitely not. 'The Forger' is a work of fiction. It was crafted by the creative team to provide an entertaining and captivating story that doesn't draw from any true incidents.
One great Loid x Yor fanfic is 'A Spy's Heart'. It delves into the deeper emotions of Loid as he starts to truly care for Yor beyond their fake marriage setup. It shows his internal struggle between his mission and his growing feelings.