I don’t have a routine now & haven’t practiced one since, but in High School my speech therapist taught me a 20min routine that I practiced for a year. It consisted of making sounds, shapes with your tongue, massaging the tongue, and repeating phrases very slowly. I had some improvement but nothing significant. I have however been playing with an app titled “Simply DAF.” You use earphone to listen to yourself talk while you’re talking (idk if that makes sense). Speaking very slowly while at a high (300-150ms) can really help articulation. And amazingly, using the app at around 50-70ms can improve a stutter significantly.