In my case, I was prayed for in a Breakfact meeting of the Full Gospel Business Men's Fellowship Iinternational (FGBMFI) back in '73. And the prayer was that I would receive the "Baptism in the Holy SPirit".
Nothing detectable happened.
I'd been Christian for 11 years at that point, and had, about a year previously had a "Crisic Experience" related to Peter's experience in John 21:
15 So when they had dined, Jesus saith to Simon Peter, Simon, son of Jonas, lovest thou me more than these? He saith unto him, Yea, Lord; thou knowest that I love thee. He saith unto him, Feed my lambs.
16 He saith to him again the second time, Simon, son of Jonas, lovest thou me? He saith unto him, Yea, Lord; thou knowest that I love thee. He saith unto him, Feed my sheep.
17 He saith unto him the third time, Simon, son of Jonas, lovest thou me? Peter was grieved because he said unto him the third time, Lovest thou me? And he said unto him, Lord, thou knowest all things; thou knowest that I love thee. Jesus saith unto him, Feed my sheep.
The KJV English obscures the meaning of the passage, since Jesus uses the word "Agape" for love, and Peter answers with "Phileo" - essentially saying "not really" to Jesus' question.
And the Holy Spirit turned the tables on me, and asked ME the same question - do YOU LOVE (Agape) Me??
And, of course I had to answer as Peter did: Not really. I Understood that not to be acceptable, and I did a "house cleaning" of all the THINGS (Mostly hobbies that I was obsessive about), and turned my attention to Reading the Word - about 3 times through that year. It seemed like a good start. And I got exposed to some teachings by Derek Prince, and Bob Mumford and others that clarified some things.
I, for a long time, had intellectually accepted the CONCEPT of a "Second act of grace" - since it was something that I found in the testimonies of any number of teachers, and pastors across the board in most denominational groups for hundreds of years. THEY didn't call it "the baptism in the Holy Spirit", but the EFFECTS of it were similar - a "Power in ministry" a greater desire for the Word, a more effective prayer life, etc.
Spurgeon called it "Being filled with the Holy SPirit", Baptists called theirs "Perfect Submission" Oswald Smith called it "The enduement of power", Wesleyans called it "Being Sanctified Wholly", and of course the Pentecostals called it "Baptism in the Holy Spirit" - AND taught the doctrine of "Initial Evidence" - tongues - which was the way the "Package" generally came in the '70s.
In any case I was prayed for - and NOTHING overt happened - until the next Dinner meeting of the Sidney, OH FGBMFI. We had just finished dinner, and they were in a time of musical worship, and in the middle of THAT, an unfamiliar word appeared in my mind. SO I spoke it, and more unfamiliar words just began to flow through as I spoke them. There was NO "Emotion", or other reaction - OTHER THAN the realization (with a certain satisfaction) that I was actually "Speaking in tongues", and that I could do it as long as I felt like it, and it just continued to flow.
But that was all there was at the time, but about three weeks after that, I attended a "cottage Bible study" among folks from the United Church of Christ (Not the Campbellite denominations), and the asked me a Biblical question.
And I wound up teaching that group for the next 4 years, and several others for the next decade - being "Fed" what to present the night before by the Holy Spirit. It was NOT anything I could have done before - teach the Word extemporaneously for a couple of hours, as the Holy Spirit led.
SOME people have well-nigh CATACLYSMIC experiences when they are Baptized in the Spirit. Bellow in tongues for Hours, see visions, experience FANTASTIC excitement, get slain in the SPirit, etc.
I didn't, never had much "Emotional reaction" to it at all, and I've NEVER been "burdened by the Spirit" to deliver a "Message in Tongues" in a church meeting.
I HAVE been burdened many times to Interpret tongues spoken by others, and to give prophetic utterance, which gifts work just like tongues, except that the words that "Flow through" are in English.
Simple as that.
P.S. in the years before, in the Assemblies of God (where I'm still a member), I did participate in any number of Pentecostal "Back rubbing sessions" trying to "Get Filled". I had folks try to "Prime my pump" by talking baby talk, or making nonsense sounds. I was told to "HANG ON", or to "LET GO", to kneel, to lie on the floor, to wave my arms in this or that way. - Bupkus.
But that evening in 1973 - I just Happened when it was supposed to.