Well, that's a vague question so let me make a few suggestions. When I do my pre-screening phone & emailing I make sure they live or work near me so I'm not out of their way, that their hours are going to be within my work hours, that their child is an age that will fit in here, that they know my rates and a few of my basic rules.

Then during the interview I'm watching closely to see if they are overbearing personalities or if they are willing to respectfully work together with me, if they are overprotective parents or relaxed and normal so they won't be freaking about little things nonstop, if they understand that I will terminate them if they don't follow all policies in my contract and that I am willing to always go the extra mile to work with them but won't bang my head against the wall so to speak.

I'm being very blunt now, but I'm telling the truth. When I interview families I'm honest and after I sign them on I'm honest because I tell parents the good and the bad and celebrate the great milestones with them and their child but expect them to be consistent with me and advise me as I advise them on how things are going with behaviour modifications as the little ones go through stages.

Ok, those are some of the things I look for in a great client. Now you think about what you really want in a great client. Good luck!