I actually had an editor tell me this long ago, and now I'm sharing it because I'm seeing it more and more. So, here goes:
Can you pick the correct sentence?
A. "How could you?" she hissed.
B. "You'll pay for this," she hissed.
C. "Leave me alone," she hissed.
If you answered B, you are correct. Tell me, how do you hiss a sentence without an S? And yet, you see the word hissed used as a dialogue tag all the time in sentences such as A and C. WRONG!
So when you find yourself using HISSED as a dialogue tag, stop and look at that sentence. If you're saying "Your ass is grass!" you're on the right track. You can really hiss that! Try it. Say it out loud. Your assss is grasssss.
But if you are saying "Leave me alone," eh...
Have a fantasssstic day!