One common theme is the power of friendship. Their bond helps them both grow and overcome their respective traumas. For example, Naruto's friendship gives Gaara a reason to believe in himself more.
One popular 'naruto and gaara childhood friends fanfiction' is 'The Bond Beyond Sand and Leaf'. It beautifully portrays their friendship from a young age. It shows how Naruto's positive attitude starts to influence Gaara even in their early days.
In some fanfictions, Naruto and Gaara's childhoods are paralleled. Both were outcasts in a way. Naruto was shunned because of the Nine - Tails inside him, and Gaara was feared for the Shukaku. A fanfiction could explore how they might have found solace in each other's similar experiences, had they known about it earlier.
For Gaara, his friendship with Sakura could make him more open and trusting. Instead of being feared, he would start to show his softer side. Sakura, meanwhile, would become more empathetic towards those with troubled pasts. Her experience with Gaara would teach her that there's more to a person than what meets the eye.
Often, a battle or a common enemy can be the catalyst for their friendship in fanfiction. Let's say there's a new, powerful foe threatening both Konoha and Suna. Naruto and Gaara are forced to fight side by side. During this time, Naruto's unwavering determination and positive attitude start to influence Gaara. Gaara, in turn, shows Naruto his own strength and loyalty. This shared experience of facing danger together makes them respect and like each other, thus forming a friendship.
One common theme is redemption. Gaara was once a troubled and lonely character, and through his friendship with Naruto, he finds a path to redemption. Another theme is acceptance. They accept each other's differences, like Naruto's boisterous nature and Gaara's more reserved personality.
One common element is the exploration of their loneliness. Gaara was alone because people feared him, and Naruto was alone as people shunned him. Fanfictions often focus on how they coped with this solitude.
One possibility is that they could have supported each other during tough times. Gaara, with his lonely childhood, might have found comfort in Sakura's kind heart. Sakura, in turn, could have learned about Gaara's unique abilities and the hardships he faced in the Hidden Sand Village. They might have shared secrets under a big tree, away from the prying eyes of others.
Perhaps they could start a training program for young ninjas from both their villages. This would not only strengthen the bond between their villages but also give them a chance to teach the next generation their values. In the process, they'd face challenges from traditionalists who don't want to change the old ways.
Well, it could be really amazing. They could go on adventures together, like exploring new jutsu in the forest. Maybe they'd help each other train and become even stronger. They might also share their life stories and secrets, strengthening their bond as friends.