I'm not sure there is anything that is 'most effective.' It's a program. A ladder, if you will. *I believe the therapist is an integral part of the process.* I'll run through a thousand foot view, but I can't emphasize enough that I don't think this works without the guidance of a professional. Going back to the gym analogy. A trainer will help someone use proper form and best practices. They help you correct mistakes before you form bad habits. I was taught these under the guidance of a speech therapist. During my weekly sessions, they would correct me as I performed the exercises. (It just occurred to me that music lessons might be a better analogy...) I often equate fluency to a habit. You practice and develop the habit of fluency. For me, my stuttering was aggravated by my bad habits. I went from my initial stutter, to seeking alternate/replacement words. Then I started adding 'um' as a way to avoid the stutter. "um" became a habit. It went from helping early on, to being part of my stutter. I added "the" when I felt a block coming. It evolved into "thee, umm" being repeated over and over. My point being, when seeking fluency, you want to develop good habits. You want guidance and feedback, so that you achieve your fluency while avoiding pitfalls. Under the guidance of a speech therapist, during my weekly sessions, they would correct me as I performed the exercises. Under guidance and with practice, these techniques become second nature. But initially, you have to be conscious of your techniques and methods. I remember one of the initial instructions was "Don't try this at home or outside of therapy yet. We'll get to that later." They want to make sure I got it right in therapy first. Then get practiced at it, before I started introducing changes to my speech outside of therapy. Thousand foot view... (And this is from the 80s and 90s. Techniques may have advanced. I won't remember everything either.) Breathing. You have to be able to breath to speak. If you run out of breath, you're done. Nothing will come out. So you take a breath before every sentence. Start exhaling before you start speaking. With the exhale started, you then begin to speak. Continue your exhale throughout speaking. If you run out of air, stop. Mush mouth. No hard sounds. Soften any sounds that hit your mouth hard. If you're saying a word with the letter B, you never bring your lips all the way closed. Remember, the exhale is continuous. Never stop your air flowing out. Same with T sounds, K sounds, etc. Everything is soft and mushy. ** This is a temporary step. You won't be mush mouthed at the end of the program. But early on, you're taking baby steps towards fluency. Monotone / mush. You practice the mush / monotone one word at a time. Start your breath, read a word aloud. Slow and deliberate speech. You work down a sheet of single syllable words. Three words sheets. More mush, more single syllable words. But three at a time. Breathing through each sentence. Longer sentences. Mush, monotone. Maybe multisyllable words? I recall this is where I had to refocus on breathing. I would sometimes neglect to take a proper breath before getting started. I would run out of breath before the end of the sentence. (Two steps forward, one step back - lol) Not that they were long sentences, but you're passing a lot of air, and speaking slowly. IIRC this puts me a few months into therapy at this point. No improvement in my fluency outside of therapy yet. Still working toward that. But I was practicing the sheets at home, alone, by myself. And it's like 10 or 20 minutes a day. Once proficient at these practices, they started having me transition from mush / monotone to regular speech on the last word of the sentence. This was a really hard thing for me to learn. I don't know if I have an analogy... It's like shifting gears on a manual transmission, but I was dumping the clutch. It took time and practice to get that transition right. You're still hitting the hard sounds soft, but the rate of speech is what you're transitioning from slow to normal. I often would go from slow to rushed. Even though I sounded super weird at this point, I was achieving fluency. I'd spend an hour speaking with the therapist, and was totally (or nearly so) fluent. That alone was a huge boost to my mental health. As I achieved success, the therapist moved the transition point forward in the sentences. Most of the sheets were the same ones I had read for months, but they'd add a tick above the space between the words where I needed to transition. Things were moving quicker now. I went from last word transition to last few words, to halfway through the sentence, to first three words, first two words, first word, first syllable... I promise you, no one in the real world is listening so closely that they notice my soft start on the first word or syllable of my sentence. It's somewhere around this point where they had me start using my fluency outside of the therapy office. Start slowly. Use it once a day. Use it a few times a day. Build a history of successes. There's more to it than this. There were the physical reinforcements that I did that associated with monotone vs regular speech. Closed hand vs open hand, for instance. Start speaking in monotone with a closed hand, and open it when I transitioned. I think it started with raised hand v lowered hand. Then closed hand v open hand, then pinched finger v open finger. Eventually becoming pressing my finger on something for monotone, and releasing during the transition. Someone here mentioned the Delayed Auditory Feedback device. The therapist had me use it for a brief period during one session. As I understood it, the DAF was there to show me that I could be fluent. It wasn't any type of a solution to stuttering. I can't tell you what else I've forgotten, but like I said... This is a thousand foot view of the program that helped me. I can't imagine any of this working without a proper therapist. This is the program that I experienced. I don't know that this was a standard program, or if they adjust programs based on the needs of the stutterer. I would guess they tweak it for the needs of the patient. Probably not what you were asking for. I'm sorry. It's my belief that any of the exercises I described don't work unless they are part of a program.