None of these helped me, because I didn't have the poses they showed in tutorials, nor were my pictures of the same quality. Consequently I directed my attention to the movie's own promotional ads, more specifically this one:
So I went ahead and took a picture of my hand with some crappy cotton black Halloween glove I had laying around with a really old Joker card from a normal card deck and grabbed an old picture that had no real purpose besides just taking space from my preciously limited Hard Drive.
I started doing this after watching the movie the day after it came out. It was mostly rushed but ended up better than I expected, but my expectations weren't that high anyway.
The only thing that's not mine are the teeth, which I took from some random Google Image Search result bastard.