For me, the trick to getting started in presenting in the technical community was to find something which made sense to me, but that other people found hard. I think from memory, the first thing that I presented was a .Net thing – maybe AJAX? – and I explored the things that people typically found hard, showing why it was easier than they expected.
…and it was no different to telling a story to a group of people at a barbecue, or around the water cooler.
Let me use Sargability as an example, and show you how the water cooler conversation goes:
Person 1: Rob, why did you change my query this morning?
Me: Because it was performing badly, and all you needed to do to fix that was to apply a dateadd on getdate() instead, of doing a datediff between your column and getdate().
Person 1: But why should that make a difference?
Me: Well, you have an index on your column, not on the difference between your column and now.
Person 2 (see – there's a group!): Yeah nah, I saw the plan, and that index was being used.
Me: Sure, but it was a Scan, not a Seek. It was having to work out the datediff on every row and see if it was small enough.
…and you see you have the basis of a presentation. If you can explain it to a few people, and find ways to help them understand it, you can explain it to a larger group.
You might be fine about demonstrating a concept to a co-worker on your computer – so there's the demo section of your presentation. You don't need to use slides (I don't!) to present to a crowd, you just need to see how to explain things in a way that they can connect to – addressing their problems and giving them confidence in your solution.
I think the trick to being confident on stage is to know that you're the expert who has the answer they want. When you have an abstract that explains what scenario you're trying to solve, people are coming along to listen just like they'd gather around your desk to listen. They want to know the answer, and they're on your side. They're not trying to beat you down – they genuinely want to learn. You might have the odd person in the crowd who wants to argue that they're the real expert, but if you know your stuff, you can disarm them with things like "I love that you've pointed out that the index does get used, because you're right, it does! Just having that index helps a lot – but I want to show you how to use that index in a better way."
You can work off the people in the room the same way you can work off the people around your desk. When someone at your desk says "Hang on, what did you do there?", you know that you should be more careful when explaining that to a bigger room, and invite them to come along the journey with you.
Presenting is a great way to give back to the community, and that's why I've written this piece for T-SQL Tuesday this month. The community wants to learn from you – so let them do just that!