I saw an Orthophonist from the age of 9 to 12 for my stuttering which was "worsening" over time.

He gave me a trick which overtime had a massive impact on the severity of my stuttering.

The trick was to imagine a river if you will when you "feel" the block approaching. The idea behind that trick is to force yourself to concentrate and consequently lower the rate at which your speaking. It doesn't necessarily avoids the block. It does make you concentrate and gives you enough time to recompose yourself and try to avoid the stutter.

He would say "Speak as the flow of a river", if you have the same imagination I have, I'd wouldn't be surprised if that sentence helped you.

Essentially, he was trying to force me to automatically concentrate on the rapidity of my speech when I felt a stutter was right around the corner. It was one of the few tricks I still use today and made me almost stutter free (I sometimes stutter at the punchline of a joke or in other high pressure situations).

This trick was a good 7 out of 10.