I'm an effective public speaker and really enjoy it (especially the responses I get afterwards). Here are a few of my tips:

1. Rehearse your presentation enough beforehand (including immediately before in another meeting room if possible) such that you are able to run on auto-pilot after the first few minutes. Can't emphasise how crucial this is.

2. Conduct your presentation so you're speaking naturally about particular points, rather than trying to remember an exact script (the act of trying to remember what you are "supposed" to say may be causing you anxiety). If you have rehearsed enough, and know enough about your subject, it should be possible for you to do this.

3. Recognise that you might need to write a script to begin with, when preparing your presentation. This can help ground you, and gives you something to start from. Once you have rehearsed it a few times, you should start developing a "rhythm" that feels more natural to you, and this is when you can start "winging it" a bit more. There is nothing whatsoever wrong with bringing your script / notes with you on the day. This will give you a feeling of security (you have a backup in case you freeze). By the time the end of the presentation rolls around, you may find you never needed to unfold your notes at all.

4. You will always feel nervous in advance, to some degree. This degree is lessened with lots of prior rehearsal, but it will still be there. Accept it as normal, and don't think that because you're nervous you are destined to fail. After the first few minutes, that's when your "flow" will start kicking in, and things will begin to happen naturally.

5. When developing your presentation, try to empathise as much from the audience's perspective as possible / take a very skeptical view on your material. If you then convey your presentation in this manner, you will easily be able to get your audience on side with you. This helps you get to the "flow" state more quickly than if you are talking at odds to people, and they keep their wall up.

6. Hopefully you are presenting about something that you are interested in or passionate about, or at least know enough about to be confident. Let your energy and confidence out into your presentation style. Don't be afraid to use big gestures, and convey your passion in your voice. Think of it less as a recitation of a script, and more of a powerful and fun experience that your audience is being taken along with. Think of your presentation less in terms of merely conveying dry information, but to "entertain" your audience. Emphasise dramatic flair to create interest from your audience. This comes more easily to some people than others (I have a drama background). People respond really well to this if you can pull it off.

7. Information retention in your audience increases by a lot if you get them to participate in some way. This can be more than just the cliche'd "everyone raise their hand if you have heard of X". If you do this well, and empathise with your audience's reluctance to participate (e.g. say "now I know everybody just loves these audience participation activities! /s"), they can be a really nice break to the monotony of a presentation, and is another tool to get your audience on side with you.

8. The more punchy and interactive things you can do during your presentation to grab your audience's attention, the easier it will be for you. Rather than looking out at a sea of bored faces checking their cellphones, you will see everyone's eyes looking directly at you, and can feel the expectancy in the air. This is a very powerful state to be in, some people refer to it as "holding the audience in the palm of their hand". Good luck!