Laura Seabrook's Ramblings

The first is TV TROPES which is "a catalogue of the tricks of the trade for writing fiction". I've linked to this before. There is an extensive list of entries which include examples from comics, manga and anime (as well as TV, film and so on). I found this to be hilarious to browse through. For example,

Put On A Bus is "a character is written out of a series in such a way that they can easily be returned later, if the producers so choose. They are Put On A Bus " and an example of this from comics is "Between the late 1960s and his return in the early '80s, J'onn J'onnz, the Martian Manhunter of the Justice League, went off to find "New Mars" with the rest of the Martian people. This has since been retconned — along with the existence of other Martians in general. "

Turkey City Lexicon is a much smaller list detailing overused techniques and shortcuts in SF stories. However, a fair number of these also overflow into comics. I particularly like...

"Plot Coupons" (The “hero” collects sufficient plot coupons (magic sword, magic book, magic cat) to send off to the author for the ending); and
"Signal from Fred" (the author’s subconscious, alarmed by the poor quality of the work, makes unwitting critical comments: “This doesn’t make sense.” “This is really boring.” “This sounds like a bad movie”).
"Card Tricks in the Dark" used to be a staple of comic plots at DC in the 60s - Gardener Fox (or some such) would pull out some amazing bit of trivia that only he and the hero knew, and use it to unravel the plot of the villain.