AUTHOR'S REPLY----Thank you, everyone! I'll update now, the first time in two days. Crap, I haven't been brainstorming.
Harry had been browsing the DA textbook that he, Ron, and Hermione had bought at Diagon Alley, what seemed like a year ago. He had discovered a extremely useful chapter, filled with even more useful spells. The chapter was titled: Impediment Spells. It was purposed to slow or impair the enemy, giving the initial caster a chance to finish them off.
Of course, the Impediment Jinx had been first and foremost in that chapter, but Harry and the rest of Dumbledore's Army had already mastered that particular spell. What Harry was teaching them now was the Epicentre Curse, or in simpler terms: the Earthquake spell.
Of course, it was rather complicated, shook the ground very violently at the opponent's feet when successfully casted and aimed.
To make the curse work, they had to focus their emotions into one big burst, and concentrate so that they were released out as the incantation and wand movement were commencing.
As Harry had predicted, Ron had been quite successful on his first try, making a very big mess in the Gryffindor common room(Harry had insisted that the Gryffindors practise first, as to give them a chance to teach the others, so they would learn faster).
Thankfully, Hermione, Ginny, Parvati, and Lavender had been there at the time, and had cleaned up nicely within two minutes.
"Household charms, I'll never master them." Neville sighed. He tried to use a Levitation Charm to put books back into the bookshelf, but he was very tired and the books lost heart halfway.
"Oh, never mind...never mind." Ginny waved her wand very carelessly and the books sailed back onto the shelf.
"You learned that from mum, didn't you?" Ron commented.
"Why yes, I did." Ginny grunted, sinking down onto a squashy armchair.
"She never told me how to do that."
"Ah, well, that's because I'm the only daughter." she smiled cheekily at him.
Ron rolled his eyes and turned to Harry. "Typical little sisters. Always manages to get spoiled." He shook his head, yawned, and scratched.
Harry and Hermione glanced at each other, and grinned secretly. It was a good sign that Ron was nearly back to normal.
**
They mastered the Epicentre Curse after five meetings. Harry was enormously pleased with all of them; every member had shown unfaltering support towards the DA, and had given their enthusiastic efforts in every meeting.
Finally, the last shouts of "Epicendium!" had died, the last torn book pages and dust had drifted to the floor. Harry was in a very good mood, and suddenly had a wild idea. It was nearly Christmas, after all, and it was a Saturday evening. Why not?
Quickly, he whispered some choice words into Fred and George's ears. They smiled, sprang to attention, saluted, and ran out the door as if their behinds were lit on fire.
"What did you tell them?" Ron said, puzzled. "Looked as if they had a Chimera on their tails."
Everyone else were also curious. Harry simply stood up and told them all:
"I told them: 'It's time for a DA post-Christmas party. Get to the kitchens'."
There was not a single person in that vast chamber that did not roar their approval; those who were closest hoisted Harry on their shoulders and carried him the length of the room, as if he had been the hero of the Quidditch House Cup. Harry made no effort to get down, since they seemed quite willing, and he did not want to diminish their spirit a single bit.
But what made Harry the happiest was Ron standing hand-in-hand with Luna, both laughing brilliantly; Hermione saw too and nearly burst into tears. Harry finally got down, and calmed her.
"Now, now." he patted her back. "I know it's wonderful seeing Ron like that again, but you can't go bawling around like that, OK? It'll alarm everyone."
Next moment, Hermione was hugging Harry, squeezing so hard that his eyes were bulging. He had to pound her back frantically to get Hermione to let go.
"What was that for?" he gasped, poking his ribs tenderly.
"Oh...well..." Hermione said, very sheepishly. "I needed to hug someone, or I felt like I'd explode. And you were closest, and we are going out..."
"I get it." Harry grunted. "Not so hard next time, OK? Actually, next time, just do a Patronus Charm or something, don't strangle anyone."
She nodded, turning red.
***
A full hour later, Fred, George, and two dozen other members had come up with enough food and sweets from Honeyduke's and the Hogwarts kicthens to satisfy everyone's appetites. Fred and George made the detours to Honeyduke's, while Seamus, Dean, and the rest invaded the kitchens(more or less "Sirs, may we give you more?" from the house-elves).
People were venting extra happiness by conjuring Patronuses and watching them blissfully, munching on various food items. Even Ron was digging in; he was his old self again.
Ah, this was a good day, Harry thought, arm around a drowzy Hermione. More than worth using for Patronus Charms. Maybe a lot of people will use this memory to serve.
And smirking at the thought, he continued to enjoy himself hugely, along with the rest of Dumbledore's Army.
**************
AUTHOR'S FOOTNOTE -- Man, that was a lot! There's an example of my "from-scratch" writing style. I actually came up with the partay idea while I was explaining the finer points of the Epicentre Curse.