Absolutely, I didn't learn this a few times because I expected the product I was freelancing on to be sold to multiple other clients meaning continued project work for me. But after a month and a half and using up some savings $$$ to pay the rent, I realized that just sticking to coding isn't enough and you have to really develop a sense of who will rip you off and who won't and insist on advanced payments or getting paid at the end of the day.

I remember reading about someone who would bill daily. If there were problems with $$ they just wouldn't work the next few days.