Learn the ancient art of tapping your forehead in a way that's almost polite.
Remember, practice makes perfect, and so does a good dose of common sense.
Or, you know, don't.
Disclaimer: Results not guaranteed. May not actually improve communication. May result in forehead injuries. May result in spontaneous combustion. May result in spontaneous combustion of nearby flammable materials. May result in... Okay, fine, don't try this at home, or do, we're not judging you.