In the fanfiction, it could develop through shared experiences. Maybe they both get involved in a dangerous situation in the Forbidden Forest. Draco is used to relying on his own wits, but Neville's kind heart and loyalty make him a valuable ally. As they fight off dark creatures together, they start to see each other in a new light. Draco begins to respect Neville's tenacity, and Neville sees that Draco is more than just a snobbish Slytherin.
Perhaps a plot where Draco and Neville are both caught in a magical mystery outside of Hogwarts. They have to rely on each other to survive. Draco's Slytherin cunning helps them avoid some dangerous traps, while Neville's Gryffindor courage gives them the strength to face the unknown threats head - on. As they go through this adventure, they develop a bond that surprises their friends back at school, and they end up changing the views of their respective houses about the other.
I really like 'Draco's Redemption and Neville's Forgiveness'. In this fanfic, Draco is trying to make up for his past wrongs during the war, and Neville is the one who helps him through it. It delves deep into their emotions and how they grow as characters through their interactions.
Ron Weasley is another strong candidate for a main character. His loyalty and sense of humor are important aspects of the story. He might be there to support Harry and Hermione, or he could have his own independent arc where he has to face his fears and grow as a person.
Expect a lot of cute and chaotic moments. The 'Rugrats' are known for their innocent yet wild antics. In a 'Best Laid Plans' fanfic, it could be about the toddlers' attempts to do something big like plan a party for Chuckie's birthday. They might gather all the supplies they can find around the house, which could lead to some really funny situations.
In a 'Best Laid Plans Rugrats Fanfic', the author could play with the relationships between the characters. Maybe Angelica is involved in the babies' plan in a sneaky way. She could try to sabotage it for her own amusement. Or perhaps the fanfic could be about the parents trying to figure out what the babies are up to, adding a bit of mystery and humor to the story.
Since there are many possible 'the best laid plans stories', the main characters can vary widely. It could be a young entrepreneur in a story who has the best plan for starting a new company. He might be full of ideas and has everything planned out, from financing to marketing. Or it could be a family in a story, where the parents have planned a great vacation for the kids, but then various things start to go wrong. There could also be a character like a scientist who has a brilliant plan for an experiment, but unforeseen factors in the laboratory environment mess up the plan.
The main idea is often about how even the most carefully made plans can go awry. It shows that no matter how much thought and effort we put into planning something, unexpected events can disrupt it.
One great 'Harry Potter' fanfiction with Neville and Draco is 'The Unlikely Bond'. In it, they are forced to work together on a school project. At first, they clash due to their different personalities and house loyalties. Draco is his usual snobbish self, while Neville is shy but determined. As the story progresses, they start to understand each other better. Neville shows Draco the importance of kindness and hard work, and Draco helps Neville become more confident in standing up for himself.
The 'best laid plans' refers to the idea that even the most meticulously thought - out schemes can fail. In the context of the quote's origin, it shows how the mouse had built its nest so carefully, yet it was disrupted by the actions of a human. This is like in our lives, we might have great plans for a project or our future, but factors outside of our control, like illness, natural disasters, or sudden changes in circumstances, can derail them.