I write for children usually, so my fan fics will be mostly about the young (untrained) witches and wizards as they learn about their magic before Hogwarts.

It was so hot that Ginny felt like her hair was melting.
“Please?” she whined again at Ron who was home for the holidays. “Fred and George went with dad into the Ministry and Percy is reading. Please take me down to the dam. Mum won’t let me go on my own.”
Ron looked up from his chess set. He’d only been pushing the pieces around vaguely for the last half an hour anyway and the magical board had beaten him three times in a row.
“If it will shut you up,” he moaned, looking just as red in the face and hot and she felt.
They grabbed some thread bare towels from the laundry basket and slipped on sandals before trudging down the hill, the grass dry and brown from the scorching sun.
“Last one in is a Troll,” yelled Ron. Finally getting into the spirit he kicked off his shoes and launched himself at the water’s edge.
His face changed from exuberance to shock as his bare feet made contact with the water of the dam. Instead of sinking into the cool relief of water, Ron’s toes touched down onto the hard slippery surface of a block of ice.