Friendship turned to more is a very common theme. Since they start as crewmates with a normal friendship in the original, fanfictions often explore how that can develop into a romantic or deeper emotional bond.
One great Zoro x Usopp fanfiction is 'The Unlikely Bond'. It beautifully explores their friendship evolving into something more. The author does a wonderful job of depicting Zoro's tough exterior softening towards Usopp, and Usopp finding new courage in Zoro's presence.
Well, in the anime and manga world of One Piece, Zoro is mostly focused on his journey to become the greatest swordsman. So, his 'love story' is not very prominent. But some fans might ship him with Tashigi because of their sword - related encounters and her resemblance to Kuina. However, it's more of a fan - created idea at this point, as there is no official, full - fledged love story for Zoro yet.
Once, my cat chased its own tail for a whole five minutes. It was so confused but also extremely hilarious. It spun around and around until it finally got dizzy and just plopped down on the floor.
In some 'usopp fanfiction', he might be the key to solving a mystery on the ship. Maybe there are strange occurrences that only his unique perspective and skills can figure out. This could involve his talent for creating gadgets and his sharp observational skills, which are often overlooked by others but prove crucial in these fictional scenarios.
One common theme is empowerment. Since Usopp is often seen as a bit of an underdog, in female Usopp fanfiction, she is often empowered to be a strong and capable character. Another theme is friendship. Just like in the original story, the female Usopp forms strong bonds with her crewmates. Self - discovery is also a theme. She may discover her own abilities and what she truly wants in life through her adventures.
One popular Usopp fanfic might be those that focus on his growth as an inventor. For example, stories where he creates new and amazing gadgets for the Straw Hat crew. Another could be fanfics that explore his relationship with other crew members in more depth, like his friendship with Luffy and how they support each other during tough times.