This is common and got me thinking as whenever people know others with the ability or resources to help them with some kind of work the common approach is to simply ask if they can help them out. Not even asking as if they are offering a job but rather as a free service. For myself, if I knew someone provided a service professionally, I would usually open it up by asking if they could help me with a job and for how much. That often opens up the conversation to discuss the specs of the project just like any other customer would.
That’s the best way to do it I find as it creates awkwardness if you are acting as if they should do it for free because they know you. Sure they could bring up the cost afterwards but it’s a little inappropriate to try and get it for free I think. If anything, open up to the fact that you will treat it like a regular customer transaction and that way it leaves the ball in their court to decide if they will do it for free.
This is not like asking your sibling in the next room if they can help you with some task quickly as an example. It keeps the relationship strong too versus people ignoring each other because they don’t want to say reject them.