I'm not very picky when it comes to drawings, so I'd suggest you just do what you do best; however, I realize some people might need a little inspiration, sooo...
I'm a huge Doctor Who fan. I don't mind if you draw the Doctor (any of them or all of them, your preferance), the TARDIS, or even an Ood, becuase everyone loves an Ood.
If your not of fan of that, feel free to draw an OC of yours, or whatever else you normally draw. I would suggest (highly encourage) you make a joke out of it. I'm a big fan of sarcasm and dark comedy, so go ahead and try to make me laugh. As long as its funny, you can't go wrong.
And if comedy isn't your thing, just draw me a christmas chicken (roasted, broiled, perched atop a building with a sniper rifle, totally your call).
I'm really not picky, just do your best, and I'll appreciate you forever.
Merry Holidays,
destroyedinsecs