The starting point is to gather too much data in order to gain focus and then edit, often, brutally.
That leads you to finding out as much as you can about your target audience. Even if you have delivered a presentation before and received wonderful feedback, a different audience can spell a different outcome. One size does not fit all! All presentations should be reviewed and tailored to the particular audience in mind.
The idea behind gathering too much data then editing and refining in order to focus, is that it will do one of two things. You will relieve your brain from going round in circles, thinking “what if” “should I include...” etc. You have already downloaded thoughts on to a page and considered them before you prune the material to gain focus. Secondly, you will end up knowing more of your subject matter than you will be required to deliver and this will naturally build your confidence, especially when it comes to handling questions. A possible added benefit is that editing will give you perspective on your material, which enables you to expand or contract it should other speakers before you not hit their mark on timing and thereby encroach on or compromise your slot.
The golden rule of any presentation which, after all is a conversational journey that you, the speaker, are leading your audience through, is of course the usual sense of having a beginning, middle and an end but it should also FLOW. Statements link, there is a sense of progression and all the visual aids belong to one ‘family’.
The material should be cohesive, congruent with you, and polished. When giving a speech or presentation, giving the material certain finesse is where the hard work is, not merely gathering the data.