Ya gotta get paid for what ya do,small buisnesses just cant afford to carry slackers, no pay...no work!
If someone wants me to repair their boat or lawn equiptment,I have money in parts,I cant afford to be the bank,when the job is done I expect payment.
But like Striper Jim and MrBuster both said,you have to know/feel out the customer...Tell 'em pay up or sleep wit da fishes!!!!
Good luck collecting