Depends on who we are dealing with.
Respectet webmasters can pay up front or on delivery.
Webmasters we know, and have dealt with before get the same deal.
Other webmasters we offer to make a draft of the design, and if they then like it, they pay a % up front, and the rest on delivery.
If it's small design job, like a 50$ job or something, it would be no problem to pay on delivery.
But if it's something that will take a week or so, it would be bad for business to work for a week, and then not get paid.
But we will work on the design until the client is happy with it...
