How to prepare a talk for developer conference

Techniques for preparing are probably unique to each presenter. Some start by writing a paper, and essentially narrating that paper.

Personally I make flashcards - sometimes on paper, often in PowerPoint. I make a card for every major point (in no order) that i want to cover. Then I flesh those out with ancillary slides. Then I order them to make a narrative.

From there I refine it, add more, reorder, remove some, until I can do the presentation from start to end and there are no jarring jumps or omissions.

Obviously this is a faster process for subjects I know well, and where I have a specific point to make.

It's worth pointing out that it is harder to make a short presentation than a long one. Making a short one takes discipline (cut out the non-essential) and clarity (make your point clearly and with sufficient supporting material.)

Finding topics can be hard - but usually I find my topics bubble up from my own interests and conversations.

Most often it happens when I notice that something I take for granted seems to be less-well understood, or perhaps misunderstood, by the community I am talking to.

Ideally I try to focus on a take-away, something people can go home and immediately implement or apply.

Obviously the conference itself matters - both in topic, but also projected audience. The topic should take people from where they are to somewhere new - and clearly to do that you need to understand where they are, and their goals.

Should the motivation to speak not come from being involved in an interesting topic first?