Ways to improve public speaking skills?

What techniques to improve your public speaking skills are the fastest to implement? I will be pitching our business to a few VCs next week (first time doing so) and public speaking is my weakest point. I'm terrified of giving any presentation. I feel investors won't be able to see our startup objectively due to it.

First things first, pitching an investor, is not public speaking. Tips for speaking to a large audience aren't necessarily the same as that for a VC pitch.

To pitch a VC, the first thing you need to realise is that they are (mostly) human. You shouldn't think of it as you talking at the VC and the VC giving a thumbs up or thumbs down - you're not a gladiator and they are not the emperor.

You should be aiming to have a conversation with the VC, but in order to get to the conversation, you need to tell them some stuff, so that you have something to talk about.

Remember that the slide deck is there to support you, not the other way around. So build it with only the information critical to the viewer. As a bonus, once you've built the deck, you always know what comes next in the story, so you don't have to worry about getting lost.

The better you know your material, the easier you will find it to have a conversation. By this, I don't mean rehearsing a speech until perfection. You'll sound like a robot, and if you do get off track, you'll struggle to get back into the flow. Ideally you'd make sure that for every slide you have, you can talk about the subject in multiple ways. Once you know your material, you don't have to worry about getting stuck.

Practice. The more you do it, the better you'll get - and there's no substituting this.

Whilst this article isn't totally relevant, I think there's some important basic points that you'll benefit from (mostly about story telling): https://medium.com/p/c4a356fcb16e