Are you sure that's the only way?
Acts 10 records how Peter went in with Cornelius and started preaching to the many gentiles that had been gathered. As he was preaching, the Holy Spirit fell on all who heard the Word. There is no indication of any laying on of hands.
It also records how those same gentiles received the Spirit before being baptized.
Acts 10:44-48
44 While Peter yet spake these words, the Holy Ghost fell on all them which heard the word.
45 And they of the circumcision which believed were astonished, as many as came with Peter, because that on the Gentiles also was poured out the gift of the Holy Ghost.
46 For they heard them speak with tongues, and magnify God. Then answered Peter,
47 Can any man forbid water, that these should not be baptized, which have received the Holy Ghost as well as we?
48 And he commanded them to be baptized in the name of the Lord. Then prayed they him to tarry certain days.
Now I don't see any contradiction in Acts 8 and 10. I simply see different ways in which God saved people, just as Christ healed people in different ways:
Some were physically touched.
Luke 8:49-56
Yet others weren't even physically present to receive their healing.
Matthew 8:5-17
Do we see this as a common practice? Do we see it today?
What was Acts 10 about? It was about changing the minds of Jews concerning the salvation of gentiles. It was a one off and required some miraculous events to convince Peter and the others that the gentiles were also in God's plan...
Act 10:19 While Peter thought on the vision, the Spirit said unto him, Behold, three men seek thee.
Act 10:20 Arise therefore, and get thee down, and go with them, doubting nothing: for I have sent them.
Act 10:21 Then Peter went down to the men which were sent unto him from Cornelius; and said, Behold, I am he whom ye seek: what is the cause wherefore ye are come?
Act 10:22 And they said, Cornelius the centurion, a just man, and one that feareth God, and of good report among all the nation of the Jews, was warned from God by an holy angel to send for thee into his house, and to hear words of thee.
Act 10:27 And as he talked with him, he went in, and found many that were come together.
Act 10:28 And he said unto them, Ye know how that it is an unlawful thing for a man that is a Jew to keep company, or come unto one of another nation; but God hath shewed me that I should not call any man common or unclean.
Act 10:29 Therefore came I unto you without gainsaying, as soon as I was sent for: I ask therefore for what intent ye have sent for me?
Act 10:30 And Cornelius said, Four days ago I was fasting until this hour; and at the ninth hour I prayed in my house, and, behold, a man stood before me in bright clothing,
Act 10:31 And said, Cornelius, thy prayer is heard, and thine alms are had in remembrance in the sight of God.
Act 10:32 Send therefore to Joppa, and call hither Simon, whose surname is Peter; he is lodged in the house of one Simon a tanner by the sea side: who, when he cometh, shall speak unto thee.
Act 10:33 Immediately therefore I sent to thee; and thou hast well done that thou art come. Now therefore are we all here present before God, to hear all things that are commanded thee of God.
Act 10:34 Then Peter opened his mouth, and said, Of a truth I perceive that God is no respecter of persons:
Act 10:35 But in every nation he that feareth him, and worketh righteousness, is accepted with him.
Act 10:44 While Peter yet spake these words, the Holy Ghost fell on all them which heard the word.
Act 10:45 And they of the circumcision which believed were astonished, as many as came with Peter, because that on the Gentiles also was poured out the gift of the Holy Ghost.
Who? The gentiles. How many gentiles? Peter went to Cornelius' house and his close friends. This was not a "revival" meeting in a tent somewhere...
Act 10:22 And they said, Cornelius the centurion, a just man, and one that feareth God, and of good report among all the nation of the Jews, was warned from God by an holy angel to send for thee into his house, and to hear words of thee.
Act 10:23 Then called he them in, and lodged them. And on the morrow Peter went away with them, and certain brethren from Joppa accompanied him.
Act 10:24 And the morrow after they entered into Caesarea. And Cornelius waited for them, and had called together his kinsmen and near friends.
How about...
Act 2:1 And when the day of Pentecost was fully come, they were all with one accord in one place.
Act 2:2 And suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting.
Act 2:3 And there appeared unto them cloven tongues like as of fire, and it sat upon each of them.
Act 2:4 And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance.
or was this a one off also? Do you see this occuring every Pentecost? No, this was a very dramatic occurrence which resulted in the birth of the church.