In a novel I am currently writing, characters frequently express thoughts. Following the advice I found here, which states: "Never use quotation marks for thoughts, even if those thoughts are inner dialogue, a character talking to himself. Reserve quotation marks for speech that’s vocalized." It generally seems to be recommended to use italics when showing that a character is thinking instead of talking.
That's all fine, but now I am running into the problem that I also need to add emphasis sometimes. For example: "And what have you done all this time?" I usually also do this with italics, since boldface is too strong - It literally catches the attention too much.
But now my (probably stupid) problem: What do I do when a character is thinking something with emphasis? Example: He thought Yeah, YOU'RE one to talk. Now, I could just use capital letters, as I did here for illustration purposes, but these look very unprofessional to me.
Does anyone have any advice on how to circumvent this problem?