All The Tropes:What Do I Call This Entry?

"''Q: What makes a good entry title? A: Short and snappy."

You are building a handle that can be used to pick up a concept and carry it around. If the title does not fit in a sentence, it isn't of much use. A title like Genre Blindness almost doesn't need an entry to carry the concept. If you can boil it down to a noun and an adjective, or even better just a noun or adjective, you've got winner.

See also Trope Namer Syndrome and Everything's Worse With Snowclones.

But Not Too Short
If you shorten the proposed name down to a TLA, expect somebody to come along and move your trope to make way for a disambiguation page. There are only 17,576 possible Three-Letter Abbreviations, after all - by now, most of them mean more than one thing, and what comes to mind when you think of a TLA isn't necessarily what comes to somebody else's mind. (For example, there are hundreds if not thousands of people who hear "BFG" and don't immediately think of Roald Dahl's book Big Friendly Giant.)

Make sure the trope name means something on its own.

For brainstorming on an idea, see the Trope Talk forum and the Trope Workshop.