Training for Public Speaking
The best advice is to employ a public speaking coach!
Whatever the presentation or venue, public speaking is not an easy art, so look for help. Since there are a multitude of companies out there all willing to offer you public speaking training and courses, there are many things to look for when deciding the training that's just right for you.
Focus on the positives; never the negatives
Any training you undertake to become more successful at public speaking should always focus on the positive aspects of what you know you already do well. Nothing can undermine confidence more than telling someone what they might not be doing well or even what they cannot do.
You already do many things well in your life so public speaking training should develop the abilities and personality assets you already possess instead of telling you what you shouldn't do.
Ignore too many 'rules'
If you find a public speaking course that looks like it's full of unbreakable rules, then pass it by! Your brain is going to be so crammed with whatever it is you're going to be talking about that to try to further stuff it full of a whole slew of rules and regulations will just be unproductive.
In a nutshell, aside from physical violence; law-breaking incitement, or inappropriately undressing, there are really no hard and fast rules about public speaking. You will need to conduct yourself in a manner befitting the audience and the occasion. This holds whether you're doing an impromptu stand-up in an East End club, or addressing members of the Royal Family in the audience as compère at a Royal Variety Show performance.
Remember: Be yourself and don't be a mimic
Essentially, quality public speaking training will treat you as an individual, making use of your own personal quirks and foibles. You are yourself - you are what you are - thus your training course must assist in bringing out that individuality; not try to turn you into someone you're not and never will be.