Work: I'm sorry, can you repeat that?

It's a phrase I repeat often. 'I'm sorry, can you repeat that?'
There are  a number of reasons I might ask you to repeat something:
1. Your phone broke up, or cut off the first part of what you are saying. That's usually a problem only with numbers.
2. You talked over me. Happens way too often.
3. You're not talking into the microphone of the phone. You're fading in and out and sometimes saying something important while your mouth is too far away.
4. We have a bad connection. It isn't my phone or my headset, but it may be that in the transfer process something got glitched. You might not hear me well either.
5. You were trying to say something while I was trying to look up something else. You didn't have my full attention because you're making me do more than one thing at a time.
My advice?
1. Don't call from the phone you're calling about.
2. Don't use another cellphone if you can help it.
3. Don't call when you're drunk. It happens.
4. Don't talk over me, and then say 'Hello?' That is sooooo annoying for my part.
5. I'll reiterate: Don't talk over me. I'm trying to either gather information from you or solve your problem.
6. Don't yell into the phone with your mouth right over the mic. It distorts your voice.
7. The other extreme: don't talk from too great a distance.
8. Please, don't use speakerphone. Speakerphones are one of the reasons number 1 above happen. i.e., it cuts you off at the beginning.

That's it for now. I may have more tips later.