Whether to the crowds....
Then Philip went down to the city of Samaria, and preached Christ unto them.
Acts 8:5
--OR--
one on one individually.....
And he arose and went: and, behold, a man of Ethiopia,.....and sitting in his chariot read Esaias the prophet. Then the Spirit said unto Philip, Go near,..... And Philip ran thither to him, and heard him read the prophet Esaias, and said, Understandest thou what thou readest? And he said, How can I, except some man should guide me? And he desired Philip that he would come up and sit with him.
Acts 3:27-31
"God would be better pleased to have six truly converted to the truth as the result of their labors than to have sixty make a nominal profession and yet not be thoroughly converted. These ministers should devote less time to preaching sermons and reserve a portion of their strength to visit and pray with those who are interested, giving them godly instruction,..."
Testimonies for the Church vol.4,p.317 E.G.W.