Crescentgray
CG: Sorry sweetness, the muse is talking.
Derek: What's she saying?
CG: She's saying, "Write, bitches!"
That being said, here are the conventions I use: Single words or short, incomplete sentences that are italicized are there for emphasis.
Completely italicized sentences will almost always be thoughts, though I try to be good about tacking on “she mused/he thought†or whatever to be clear. Unfortunately, sometimes the sentence just doesn’t flow as well when I do. If a word in a fully italicized sentence is not italicized, that is for emphasis as well.
Anything in parenthesis that is italicized is definitely a thought from the current POV character, but these are generally those random, flitting thoughts that people think but barely register on the consciousness radar. Finally, I am proud of the fact that, in the space of five sentences, I used the word italicized five times (not including that last one). I so totally rock.