What's the most common microphone mistake people make?

I feel like there are a lot of small things that instantly ruin mic quality without people realizing it.

• Too far away: echo and room noise
• Too close: distortion and plosives
• Wrong direction: muffled audio
• Echoey room: everything sounds like it was recorded in a bathroom

And the funny part is, most people only notice it after someone tells them.

I'm curious: What's the ONE mistake you see people make the most?