For Pro90D, most of the major techniques like modeling (mimicking or imitating someone who speaks well), affirmations, and free flow speaking (take a deep breath, then speak continuously until you run out of air) are all in the YouTube channel of Michael Williams. Pro90D has a lot more to offer than these. As for the program at the Speech & Stuttering Institute, it has the classic techniques like gentle onset, how to breath from the diaphragm, amplitude contour (this is pretty much the same as free flow speaking from Pro90D), and a bunch of other things that attempt to reconstruct your speech. It also has sections in the handbook tag "Cognitive Restructuring" that attempts to address the psychological effects of dealing with a stutter and aims to change your mindset about how you see yourself as a speaker. Tell me about the techniques used in the programs you attended.