I prefer contact via phone. I put in my advertisements that I do not accept email enquiries and to only call in the evening or on the weekend. If they call me during the day I just tell them to call later. I find that otherwise you do lots of messaging back in forth with alot of time wasted, where a 5 minute phone conversation would have covered everything. You can get such a better feel about a person by actually talking to them. I also feel that you are getting families that are seriously interested, as they must actually pick up the phone! But I have had lots of job experience that required talking to people in person and on the phone, so phones don't scare me. Lol
Once a family is signed up, I am more willing to accept correspondence by text or email. But I am one of those people that has resisted texting and only do it if I have to.
As for interviewing, I talk to them about their needs on the phone first, then schedule interviews. I will do several for a spot if there is interest, so that I get the best fit for it. I don't do first come first serve, and yes it does suck turning people down but I think it is part of the job. I think being able to tell people 'no' in a professional manner is an important skill to have too.