One possible plot could be Garble trying to prove himself to Rainbow Dash. Maybe he starts off as his usual rough self but gradually changes as he gets to know her better. He could be involved in some sort of flying competition where Rainbow Dash initially underestimates him.
Another plot might be a story where Garble and Rainbow Dash are forced to team up against a common enemy. This enemy could be threatening their respective homes or friends. As they work together, they start to understand each other's strengths and weaknesses and develop a grudging respect for one another.
A third plot could revolve around Garble being outcast from his own group and Rainbow Dash taking pity on him. She decides to help him find a new place in Equestria. Along the way, they face various challenges together, such as dealing with other ponies who are suspicious of Garble, and in the process, they form an unlikely friendship.
First, understand the characters. Garble is a dragon with a tough exterior, while Rainbow Dash is confident and loves flying. Make sure their personalities shine through in the story. For example, Garble could be stubborn but have a hidden soft side. Second, create a conflict. It could be something as simple as a disagreement over territory or a more complex emotional struggle between them. Third, have a satisfying resolution. Maybe they learn to co - exist or even become friends.
A common plot is Rainbow Dash's journey to join the Wonderbolts. This often involves her facing tough auditions, competing with other ponies who also want to be part of the team. For example, she might have to prove herself in a series of flying races or stunts.
There's 'Rainbow Dash in the Abyss'. This fanfic could take Rainbow Dash on a journey into a dark and mysterious place. Maybe she gets lost in a strange, dark dimension where the rules are different and she has to use her wits and courage in new ways. It could show a side of her that we don't often see in the normal MLP stories.
A great mlp baby rainbow dash fanfic could revolve around her relationship with her parents as a baby. Maybe it shows how they encouraged her love for speed and flying. They could have told her stories about famous fliers in Equestria, which inspired her to dream big even at a tender age.
One common theme is friendship. Just like in the main MLP series, the relationship between Rainbow Dash and the OC often revolves around learning about each other, being there for one another, and growing through their friendship. For example, in many stories, the OC might be new to Ponyville and Rainbow Dash helps them fit in.
Perhaps a story where Scootaloo discovers a new type of flying trick and wants to show Rainbow Dash. Rainbow Dash is initially skeptical but then realizes the potential of the trick. They then work together to perfect it and show it off to the rest of the ponies in town, promoting the idea of innovation and friendship in the process.
One possible plot could be that Rainbow Dash gets into a dangerous race and has an accident that results in her death. Her friends then have to come to terms with the loss and remember all the good times they had with her.
The MLP fandom has a rich variety of fanfiction that focuses on character development, adventures, and the relationships between the ponies in a positive light. For example, there are many stories about Scootaloo and Rainbow Dash's friendship, where they support each other and grow together. These are the kinds of fanfictions that are worth exploring rather than ones with inappropriate themes.
Some plots may revolve around self - discovery. Rainbow Dash and Rainbow Blitz could be turned into humans and have to figure out who they are without their pony identities. They might learn about human emotions and relationships in a deeper way. There could also be a plot where they are training humans in the ways of the ponies, like teaching them about loyalty and friendship. Or they could be on a quest to find a magical item in the human world that has some connection to their pony world, facing many challenges and making new friends along the way.
There's also 'Rainbow's New Companion'. In this fanfiction, the OC is a shy and introverted character who initially is intimidated by Rainbow Dash's boldness. But as the story progresses, they form an unlikely bond and go on adventures together, facing various challenges in Equestria.