I went to a bit of group speech therapy for people with stutter, which I highly recommend if your country offers any, and I learned a couple of techniques. The first one they called “on-time” which essentially used to lower the amount of complete blocks. Once you reach a block, you’re supposed to stop talking, take a deep breath and right before you start breathing back out, you try saying it again. A second one I learned was a personal one because the therapists noticed how I would hold my breath trying to speak while in a stutter, so they recommended trying to breathe out while trying to speak in a block.