One possible druid idea requires you to go back to the character's childhood. I'll relate the backstory of one of the top druids in my campaign world. I admit, it's a bit derivative, but it worked for me.
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Corim Kelthum was an unexceptional infant being raised by loving parents. The unexceptional Kelthum home was far from any large cities, and Papa Kelthum made an unexceptional living as a farmer and animal husbander.
One morning before dawn the Kelthum household erupted in terror and chaos when Mama Kelthum found the month-old infant Corim missing from his crib. Because she'd seen a few earthy animal footprints in the baby's room, she assumed the worst, and her screams woke Papa and Corim's three older siblings. After a frantic search of the house, Papa comforted Mama as the older children fanned out in the early morning light to search the farm, and the nearby light woods, for the culprit.
When oldest brother Jaris found Corim alive in a faerie ring in the woods, gentle sunbeams illuminating the sleeping infant, he was both relieved and perplexed. But Jaris dutifully brought Corim home and the Kelthums' day slowly returned to normal. The incident still horrified the family, but for the next month things remained entirely unexceptional.
Corim ended up disappearing from the house on the night of the new moon every month. The Kelthums, at their wits' end after only a few months, tried everything they could think of, but no vigil, no lock, and no other means of protecting Corim would prevent his disappearing from the house on the night of the new moon and reappearing the following morning in the same faerie ring in the woods. When the Kelthums in fearful desperation destroyed the faerie ring, it merely reappeared when they weren't looking.
The Kelthums eked out a decent living but financially they simply weren't able to sell the farm and leave as they wanted. Instead, as Corim's second year began, the Kelthums waited for the next new moon... and did nothing. Jaris retrieved Corim the next morning, and because Corim had so far not been harmed in any way, the Kelthums decided as a family to accept this fey thing into their lives. Perhaps, reasoned older sister Karya, Corim was destined for something great.
Corim grew up with a fascination for nature: plants, animals, and even fey creatures. Mama indulged Corim one birthday with a book of blank pages; in this, Corim sketched enthusiastically and took notes. Corim claimed in later years to have spoken at length to a beautiful woman who was the spirit of a tree, but when he showed his sketch, Papa scoffed and Mama forbade any such talk. Corim's brothers and sister, though, reveled in Corim's strange tales and drawings. As the years went by, the Kelthum parents stubbornly tried to go about their lives and ignore the strange things Corim claimed to have seen and done:
- Corim once claimed that a raccoon had spotted a group of tattooed, fur-wearing elves, who stayed in the woods watching the farm for three days.
- When Papa complained that a certain dead tree was a threat to the root shed, Corim claimed that a bear had come to help during the night. In any event, Papa found the tree had fallen over away from the shed. He chopped it up for firewood.
- Corim came home from another walk in the forest claiming that a young deer had given him an antler. The antler in question was not large, but it became one of Corim's many "little treasures" he'd gathered from the forest.
Corim developed an intuitive understanding of the farm and the forest nearby. Among other things, Corim made spices from roots he'd found, applied poultices of ground leaves to the family's bruises, scrapes, and rashes, harvested wood the family used to build better furniture, and freshened the house with living flowers and aromatic plants, which he insisted should be nurtured and grown instead of cut and dried. The family ignored Corim's occasional claims that he'd actually sent animals to gather some of the things he himself had obviously found. They tolerated his insistence on never eating the flesh of dead animals: he was healthy enough, they reasoned, and Corim's own little crops of nuts and beans were doing quite well. They'd put up with his quirks; it was a small price to pay, they thought.
Papa didn't wonder why the crops grew so well; he'd been convinced when he built the house that the soil was rich here, and he thought he was finally being proven right. Mama didn't wonder why everything tasted better; some of Corim's experiments with spices, she thought, were obviously paying off. Corim's adolescence coincided with the best years in Papa's and Mama's lives: as their income increased, Jaris, Karya, and Mikkim married quite well indeed, and Jaris moved his new wife into the expanded Kelthum house.
Though he envied Jaris's happiness, Corim had no interest in marriage. Increasingly, he was feeling as though something was missing from his life, and one day the feelings roiling inside him culminated in a hard decision: he had to leave. Yep, he had to leave the farm and get out into the big, wide world -- he'd already learned everything he could about his claustrophobic little paradise. He bid a tearful goodbye to Mama, Papa, Jaris, Ayara (Jaris's wife), and Lorbis (Jaris's little nephew), packed light, and walked into the woods.
Only a few days later, Corim, well fed, comfortable, and walking easily wherever he wished, wandered into a forest clearing where he suddenly dropped his small pack. Enraptured, almost mesmerized, he walked to the center of the clearing, spread his arms wide, and fell to his knees. His respect for nature (small "n") had blossomed into realization of the holy glory of Nature (capital "N"). Still in a near-trance, he uttered the mystical syllables of his first druid spell, and suddenly he knew he had the lasting, true friendship of the jaguar that had been following him.
Since that watershed moment, Corim has traveled tremendous distances trying to figure out what's wrong with the world. For the feeling that caused him to leave home in the first place was actually born elsewhere. He tries to teach humanoids to live by making peace with nature, not by fighting or subjugating it, but a deeper sense of foreboding keeps him moving and seeking the world's troubles. There are plenty: the Kelthums never realized what a dangerous, sinister place the outside world is. Most of the organized nations in Corim's world are corrupt, decadent, uncaring, or downright threatening. War is a constant in many thousands of lives, and nature suffers under the "needs" of the "civilized" to conquer one another.
Corim longs for the peace and tranquility he grew up with, and though he knows for certain he's chosen the right path, he's grown worried that he'll never find that peace again. Corim's not afraid to thump some heads defending himself, but overall he's not aggressive, preferring an "organic" solution to most problems. He reserves a really good thump for undead, rapacious unnatural predators, and members of Evil humanoid races. Adventuring has made him somber and morose most of the time; Corim only lightens up when he's able to spend time in idle pursuits surrounded by the fruits of unspoiled nature.
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Well, that took rather longer than I'd thought, but I hope there's a helpful bit or two. Cheers!