I'm brand new to all this, so as far as feedback goes the more the merrier! I'm a dabbler, so here's a simple little sample of some Sherlock/Who dabbling. Enjoy.
Sherlock eased across the floor, icy eyes flitting around the room as he absorbed every detail. A floorboard creaked under one boot. The detective paused, and slowly revolved on the spot. Corner of the rug turned up. Left wall bleached by the sun. Window bolted. Dirt marks by the door. The empty room burst at the seams with silence.
A loud snap and a shower of dust caused Sherlock to leap back. An explosive crash heralded a cascade of debris as a section of the ceiling splintered without warning. Cement and plaster slammed onto the hardwood at his feet, and the floor groaned ominously beneath the wreckage rumbling to a halt. A cloud of dust billowed across the room as the echoes of the collapse were swallowed again by silence. Sherlock's chest heaved beneath his coat.
"Well," rang a cheerful voice, "that landing wasn't quite as I'd hoped. But all the same."
Aquamarine eyes narrowed.
A tall figure stumbled forth from the rubble, swiping at his dirty shoulders. Tweed-clad shoulders. Black pants, dusty now, and black boots teamed up with suspenders and a dress shirt to clothe a lanky and slightly awkward figure. A crimson bowtie sat askew beneath a strong chin. Thick hair curled in a chestnut tidal wave, sweeping down into hazel eyes.
As Sherlock blinked in surprise, a look of great frustration crossed the newcomer's face while he threw his hands in the air. "I've lost my fez. Again. And that one was given to me by Laurence of Arabia!"
Sherlock, for once, was speechless.
"Well, by given, I mean tossed, and by tossed, I mean hurled… oh, never mind." It was then that the stranger took note of the detective. "Oh! Hello! Is this your house?" The friendly smile faded into abashed concern. "I…may have damaged your roof. A bit."
Sherlock had more than regained his composure. "I do not live here, no. And neither do you. Although it was nice of you to…drop by. Do tell, who are you?" While he spoke, his wintry eyes were busy, flicking across the dusty new arrival. Smooth jacket: unarmed. Bowtie: tacky rebellion. Watch: wealthy; scratches and wear: active. Plus suspenders and tweed jacket: possibly artist, professor, shameless performer, or recently returned from a clumsy formal event. Shoes well worn: frequent running, likely cause being regular tardiness. Face: late twenties, which rules out professor – but the eyes… Sherlock frowned ever so slightly. Something was amiss.
"I'm the Doctor." He rocked slightly onto the balls of his feet as he said it. "Here to help."
Sherlock was unimpressed. "Doctor who?"
A knowing smile danced above the bowtie. "Just 'The Doctor.'" He hesitated a half beat before clapping his hands together and gazing about. "Now then! This house. The Gonsurvian herd undoubtedly came through this house." The Doctor moved to the window, trailed a finger along the windowsill, reversed and hurried to examine the wall on the opposite end of the room.
Sherlock crossed his arms and watched. Internally his mind raced furiously. This character made no sense at all. The detective glanced upward, examining the ragged hole in the ceiling. Impact, not an explosion, had caused the collapse. "What are you looking for?" he asked idly.
The Doctor's nose was inches from the wallpaper. "Something…spacey-wacey," he mused absently. "Which… you!"
Abruptly, he turned and paced towards Sherlock. The detective shifted his weight, a barely perceptible change, but every muscle was humming with tension. The Doctor's focus had shifted to him completely. "Why did you come here?" he muttered, peering closely at the Londoner.
A long silver gadget appeared in the Doctor's hand from the depths of the tweed jacket. Sherlock stared at the device, unable to discern its purpose. A gun here would have been obvious. This man, however, was unequivocally choosing absurd alternatives to the obvious. It was an undeniably fascinating puzzle.
Without warning, the end flared lime green and the instrument produced a pulsing, high-pitched buzz. Sherlock braced himself for some kind of attack, but felt nothing but bewilderment as the Doctor waved the thing at him from head to toe. With a flourish and a straightening of the bowtie, the dusty visitor clicked off the gadget and carefully examined the handle. "Nope… definitely human," he mumbled.
Sherlock raised an eyebrow and gave the Doctor an arch half-smile. "Well, I'm glad that has been cleared up."
Oblivious to the comment, the Doctor paced, tapping his chin with his silver tool in thought, but the sound of a car crunching up the gravel drive drew Sherlock to the window. The detective devoted a full half second to taking in the pertinent details: sparkling black sedan, recently washed and waxed, obscured plates, sunken back wheel well, tinted windows rolled up. A government official had arrived with a heavy object in the trunk.
That was most definitely his cue. Sherlock turned on his heel and, making one last visual sweep of the room, bowed slightly towards the Doctor. "I believe I'm on my way out. A pleasure meeting you."
"And you," huffed the Doctor distractedly.
Sherlock's mouth quirked in another half-smile. "No, it wasn't." And with that he strode from the room.
As soon as he stepped into the hall, the detective halted. Every instinct spurred him to leave, leave, leave, but the irritating itch of an unsolved enigma could not be ignored. He regarded the doctor over his shoulder for a moment. "Well?" Sherlock said shortly. "Aren't you coming?"