Client: We want this completed ASAP!
The client sends multiple emails asking to complete work as fast as I can. I work long hours and pull overnighters to get the work done.
I send an invoice... and suddenly the constant communication stops. Weeks later:
Client: Sorry, I can't pay you yet I have other bills to pay first.
This happened recently, to me, but it happens all the time when you work in creative fields. Remember: you're only a priority when the job's not done.