[mooreds]

I don't think you can extract professionalism, it's a matter of finding folks who already have it.

If possible, start with small tasks, and even things you could do yourself. That way you can truly judge if someone acts professionally and does a good job.

I have found some really good professional advisors through referrals, as that means both sides have more at stake (their reputation).

Also, don't stint on paying folks. Pay them before the due date if at all possible.

If using a freelancer who is good and dependable, nothing will surprise them more and move your work to the front of the line than an unexpected raise in rates. (Do this after 6 months or so of good work.)