I guess there are many ways, but the following worked for me. First learn speaking techniques to manage your blocks. For me this involved costal breathing, being very assertive on the first sound and some more. Practice these techniques in your comfort zones and then slowly expand your comfort zone. I would go out on the streets and approach strangers to practice my difficult sounds (for instance my name). First 5 approaches I would panic and block, but by continuing you slowly desensitize yourself from the panic and get calmer. After 30 approaches, I would be able to say my very calmly with the technique. After 100 approaches I can easily say my name in any way I want. However the fear and struggle of my name can creep back in after time and then I need to practice again. But what if that somewhere safe doesn't transfer to over to normal situations? >> Try to practice enough. However, if you find yourself struggling every time and the panic is too high, go to an easier situation. Practice that situation a lot and then try again in a little bit more difficult situation, but don't go immediately into a very difficult situation, make small steps. Another thing what might work to desensitize yourself from the panic and get more comfortable stuttering, is by using a lot of voluntary stuttering (I am in a programme where we call it deliberate dysfluency).