Here are some techniques that can help you stop saying "um" or other filler words:

1. Record yourself speaking and watch the video to become aware of how often you use filler words.
2. Practice what you want to say out loud and have someone clap or snap their fingers every time you say "um".
3. Writing down what you are going to say and slowing down can also help.
4. Pre-planning transitions and shifting into "presenter mode" can also reduce the use of filler words.

Hypnosis can also be a great way to stop saying "um". Hypnosis is a process that helps you become more aware of your thoughts and emotions. It can also help you change the way you think and behave. When you use hypnosis to stop saying "um", you'll learn to stay calm and focused.

I hope this helps! Let me know if there's anything else I can do for you.