When I first decided to turn my public speaking into a profession I began, as is my wont, to research how best to do so. As I explored the subject it dawned on me there was more to being a good or great speaker than might first appear. I simply had not realised how much work, skill and practice you have to put into any form of public speaking to stand out from the crowd but once I did I put myself under an intense 12 month ‘apprenticeship’ of learning.
One of the learning methods I adopted was watching other speakers to find out what they did that was both good and bad. There is such a wide variety of speakers ranging from those that deliver for their employers, workshop speakers, conference speakers, masters of ceremonies, toastmasters…the list goes on. YouTube became one of my best resources as did watching live performances, showcases and turning up for meetings at my local Professional Speaking Association.
One of my passions is cooking so the best analogy I used to help me visualise how I wanted my talk to look and feel was sugar-work.
If done right the melting of sugar to just the right temperature and then spinning it into fantastical sparkling shapes or delicate bejewelled baskets can bring gasps from your audience and get them salivating to try your creation it adorns. I have seen many great speakers who epitomise this with their spoken word and it is towards this I aspire.
Sadly I have also seen other examples of what can go wrong;
If you approach speaking with the ‘fly by the seat of your pants’ attitude (ie. no preparation and no practice) then it is just like turning your back on the melting sugar. It burns, looks unsightly and ultimately leads to you throwing the pan with its contents away.
But be careful not to overwork it too. Again, just like stirring sugar continuously, agitating and over practising your talk leads to it become unmanageable, stiff and eventually your 
spoon ends up stuck fast in it!
Because I deliver bespoke keynotes each time I personally start to prepare about a month away from my booking. From 3 weeks out I do a lot of practicing, tweaking, honing and polishing what I am going to say but, a few days away from the actual date I stop.
I leave it alone and force myself not to change it in anyway.
Only in the last few hours before the event I allow myself to go over my talk once, slowly and with only minor adjustments if really necessary.
I have found that this helps me know exactly what I am going to be talking to my audience about so I can speak with confidence. But, by halting the process, it also allows me to deliver it in a fresh, natural way with my genuine nature, feelings and humour showing which, in turn, creates a personal connection with my audience.
So my advice is to stand back from your talk and compare it to whatever you are passionate about. Consider the best and worst examples of your passion and then visualise your talk in those terms before starting work on it. To use my analogy, work on creating a melt in the mouth brandy-snap rather than serving up a jawbreaker!