I always do Up + B, and then depending on my mood, I'll either do some line tracing on the bottom screen, or some other button combinations after the ball is thrown. I know it doesn't do anything, but it's a good luck ritual by this point.
If you actively hate Justin Bieber... then you don't know what "intended audience" means. Hate Twilight instead, it's far worse.
I never did down + B. My method has always varied from gen to gen, though. Right now, it's hold A when the ball opens, hold B when it closes, shake the DS when the ball shakes, pull the DS toward me after the third shake. That shaking and pulling feels especially useful on the 3DS, actually.
"Why don't you just take this picture for what it is? Teemo being stuffed and mounted by renek." - Serenderpity LoL Name: Thanamar
Back in Sapphire I stumbled across Regice unprepared and stupidly went into battle. I had only a few Pokeballs. I tossed a single Pokeball at it at full health, mashing down + B while it was in the air, and captured it.
I know that was as lucky as winning the lottery, but because of that I've been mashing down + B for over a decade.