Never ask for pay. Demand it, and refuse to work until you've been paid. There are four words you need to learn to speak without fear, and shout if necessary. Anybody who has seen GoodFellas knows what they are. The four magic words are...
FUCK YOU. PAY ME.
Clip from GoodFellas: <https://www.youtube.com/watch?v=3XGAmPRxV48>
Also, you need to watch Mark Monteiro's lecture, "Fuck You, Pay me" at <https://www.youtube.com/watch?v=jVkLVRt6c1U>.
My employers can always rely on me. But they gotta come up with my money every week.
Payroll company fucked up? FUCK YOU. PAY ME.
The client didn't pay you? FUCK YOU. PAY ME.
It's an emergency and you want me to work late? FUCK YOU. PAY ME TIME AND A HALF FOR OVERTIME.