I notify airports all the time as well. I got email addresses for the appropriate POCs for every airport within 100 miles of me, created my own UAS Notification form, and submit it to the POC 3 days before I make the flight. In the form I include my Phantom's S/N, my email address, phone number, exact address of the flight, maximum altitude for the flight, and a Google map measuring the distance between the planned location and the airport I am notifying.
This way I have a document trail that I can use in court if ever questioned on whether I got approval. I also then print out the form and carry it with me for that particular flight in case law enforcement has additional concerns.
Two of the airports are large international airports and my first calls to their airport operations numbers were met with confusion and one of them told me it was completely banned and to contact the FAA. So I contacted my local FAA representative got his POC information, provided it to the airport ops mgr, who had a talk with him, and we've had a great relationship ever since.