James Potter's birthday was always a grand affair at Hogwarts. His friends, Sirius, Remus and Peter, would plan elaborate surprises. One year, they enchanted the Gryffindor common room to look like a Quidditch pitch, his favorite place. There were floating Snitches and mini - Bludgers. The whole Gryffindor house joined in the celebration, singing wizarding songs and sharing butterbeer. James was over the moon, his hazel eyes shining with joy as he thanked his friends for such an amazing birthday.
A really interesting event in a James Potter birthday fanfic could be a wizarding photo exhibition. All the pictures from James' life at Hogwarts, his Quidditch matches, his pranks with the Marauders, etc., would be on display. His friends and family could walk through the exhibition and share stories related to each photo. There could also be a special section where people could write down their birthday wishes for James, and those wishes would magically float around the room like little fireflies.
One interesting fanfiction could be where James Potter's birthday is celebrated at Hogwarts in a grand way. All his friends, including Sirius, Remus, and Peter, plan a surprise party for him in the Gryffindor common room. They decorate it with floating candles and his favorite Quidditch team banners.
You can start by looking on fanfiction websites like Fanfiction.net or Archive of Our Own (AO3). These platforms have a large collection of Harry Potter - related fanfictions, and you can simply search for 'James Potter birthday' in their search bars.
One common theme is family. Since it's James Sirius Potter, his family like his parents and siblings often play a big role in the fanfictions. For example, his father might give him an old family heirloom on his birthday.
One great 'James Sirius Potter birthday' fanfiction is 'James's Special Day' which beautifully depicts his birthday at Hogwarts with his friends and family. It has a lot of heartwarming moments.
Perhaps James had some hidden magical ability that he was unaware of until that moment. It could be something that was passed down through his family but had never manifested before. This ability could have protected him from Voldemort's killing curse. Or, it's possible that there was a plot by some other characters to save James. There could have been a group of wizards or witches who had been secretly working to keep James alive because they knew his importance in the fight against Voldemort. They might have used some sort of time - turning magic or a protective charm that Voldemort couldn't break through.
One great 'lily and james potter fanfic' is 'The Potter Legacy'. It beautifully portrays their relationship and the challenges they might have faced. The characterizations are on point and it adds a lot of depth to the Potter family's backstory.
A possible fanfic could explore what would happen if Severus Snape had to save James Potter's life. Maybe James is in a life - threatening situation during a battle with Death Eaters. Snape, despite his hatred for James in some ways, decides to help him because he realizes that James is important to Lily. This event could be a turning point in their relationship, making Snape question his own feelings and James to reevaluate his view of Snape.
Friendship is a very common theme. James's friendships with Sirius, Remus, and Peter are often explored in detail, showing their loyalty and the bond they shared. Another theme is love, especially James's love for Lily. Many fanfics depict their relationship from different angles.