Well, often in these fanfictions, fem Naruto's genjutsu skills are linked to her strong will. Just as Naruto in the original had an unbreakable spirit, fem Naruto channels that into her genjutsu. She might start by using basic genjutsu to fool her opponents during small battles. As the story progresses, she delves deeper into more complex genjutsu. Her development could involve learning from past genjutsu masters through scrolls or ancient teachings. She may also face challenges where she has to break free from powerful genjutsu herself, which in turn makes her a better genjutsu user. Her skills could become so renowned that she attracts both allies and enemies who are interested in her unique abilities.
In many fanfictions, fem Naruto's journey as a genjutsu master can be developed in various ways. One common aspect is that she might have to overcome the initial disbelief of others. Since Naruto is typically known for his ninjutsu and rasengan in the original series, for fem Naruto to be a genjutsu master is a big shift. Writers may show her training intensively with a master of genjutsu, perhaps someone who saw her potential early on. She could also use her genjutsu in unique ways, like creating illusions based on her own emotions and experiences, which would be different from traditional genjutsu users. This would add depth to her character and make her stand out in the fanfiction world.