Becoming comfortable with silent pauses in your speech in key, I have found that it not only captures my audience's attention, it also calms me down. Furthermore, the silent pause should also be used purposefully as a multi-purpose tool and be inserted consciously in your speech. I have noticed that using pauses strategically helped me reduce my use of disfluencies considerably.

I agree that preparation is everything. It can mean different things for different people though. I have found that preparing a speech by writing it out and memorizing it does not work for me. What does work, is knowing as much as I possibly can about the subject matter, having a short list of the talking points or story and most importantly, the key message(s) intended for the audience.

Finally, have fun speaking. Be enthusiastic about what you are saying and put that energy in your voice and your gestures. Again, this doesn't only engage, it also makes one more comfortable speaking.

Lately, I've noticed people are saying "I mean, ...". I hear it and automatically think it's a bit odd because they did not attempt to articulate anything before that, so they did not need to restate anything.

I've noticed myself that I've done it a few times.

seems like everyone is saying "right?" and the end of every sentence this year

I know right.