I'm so nervous during presentations and meetings, how can I improve my public speaking?

Take a deep breath & remember that you are there to make a difference and a paycheck. I would try & keep in mind that it's just a few minutes out of your day that could make a difference for a lifetime.

You can practice meditation before you make your speech by actually imagining that things will go quite well ..by calming yourself down and by taking few deep breathes :)

This means you feel you don't have sufficient knowledge about the topic you are going to give a presentation on. This may be not the reality. Should give yourself some confidence.

I used to practice in front of a mirrior and then when i went in front for my speech i would foccon their foreheads or just behind their eyes so i am not looking at their eyes

Find somewhere to be alone before you speak, then? Yell. Be ridiculous. Sing nursery rhymes at the top of your lungs, skip in circles, sing a musical number! Break out and be silly and you'll be ready to conquer anything.

when you i usually go up to present i start out with A smile, it lets you focus your energy towards your facial expressions rather than figiting around with your hands.

Practice speaking in front of a mirror looking at yourself. Then find friends and practice speaking to them a few times.

Practice makes perfect. Start out by practicing your speech alone, or in front of a trusted person that you feel comfortable with. Work on your on-position motions to reinforce the image of a reassuring and self-confident speaker.

Practice in front of family, friends, or even a mirror. The more you practice, the less afraid you will be and you will be less likely to miss an important topic because it becomes almost muscle memory.

This is personally something I've struggled with and can very closely relate to. I have found that setting out to deliver the best speech possible, and imagining that scenario in my head helps. Instead of looking at the faces in the crowd I look at the people present but imagine my perfect audience in my head. This seems to provide a disconnecting affect that helps to remove me from the glare of the people present. I'm too busy thinking about my speech and what I'm saying to be bothered by the people in the audience.