Often, there's a plot where Snape discovers a new side of Harry. For example, Harry shows a talent for potions that Snape respects, and this starts to change Snape's attitude towards him. It could also involve Snape having to work with Harry on a difficult task, and through that, a bond forms between them.
A lot of these fanfics have a plot where Snape has a change of heart. Maybe he has a dream or a vision that makes him see Harry in a different light. He then starts to subtly help Harry in his studies or in his battles against the dark forces. Some might also have a plot where Snape's past is revealed to Harry in a way that makes Harry understand Snape better, and this in turn leads to a more positive relationship between them.
One common plot is Snape trying to hide Harry's identity from the dark forces while also training him in advanced magic. Another is Snape having to deal with Harry's rebellious nature against his strict guardianship. For instance, Harry might want to explore certain parts of the Forbidden Forest, but Snape forbids it for his safety.
Yes, there are. However, the quality varies greatly. Some might focus on Snape's hidden admiration for Harry's courage in the face of danger. Others could explore a more mentor - like relationship that Snape might have secretly wished for with Harry. You really have to dig through a lot of fanfic archives to find the really good ones.
There are several common themes. First, there's the theme of hidden loyalties. As Harry uncovers Snape's true loyalties, he might start to like him. Second, the theme of personal growth for both characters. Harry grows in his perception of Snape, and Snape may also grow in his relationship with Harry. Third, there's often a theme of the truth coming to light. Once Harry discovers the full truth about Snape, it can lead to a newfound respect and liking for him. Fanfiction writers like to explore these aspects to create interesting stories about these two characters.
One common theme is redemption. Snape is often depicted as seeking redemption for his past actions towards Harry. Another theme is the discovery of hidden truths. Harry might find out things about Snape that change his view of him completely. Also, the theme of an unlikely friendship or bond is very common. Despite their differences, they form a connection in many fanfics.
Another theme is the exploration of their relationship. Since they had a rather antagonistic relationship in the original books, fanfic often delves into how they could have come to understand each other better. This could involve things like Harry realizing Snape's true motives earlier or Snape being more open with Harry about his past and feelings.
A common plot is the 'what - if' scenario. For example, what if Snape had confessed his love to Lily before she chose James? This often leads to alternate timelines where Snape and Lily end up together, and the whole story of Harry Potter changes. Another plot is the secret relationship plot, where Snape has a hidden relationship with someone (could be an OC or another character) that is related to his unrequited love for Lily.
One common theme is Harry's exploration of potions. He might be on a quest to find the rarest ingredients or perfect a difficult potion.
One common theme is redemption. Snape's actions are often re - examined, and his relationship with Harry becomes a vehicle for his possible redemption. For example, in many fanfics, Snape's past actions are revealed in a new light to Harry, leading to a change in Harry's perception of him.
One common theme is redemption. Snape is a complex character in the original series, and in slash fanfics, his relationship with Harry can often be a path for his redemption. It shows that through their connection, he can find a new way to be seen and understood.
One common theme is the power of knowledge. Snape, being a very knowledgeable wizard, often uses his extensive understanding of magic to beat Harry. Another theme could be the element of surprise. Since Harry is often the hero, when Snape wins, it's usually by doing something unexpected.