There are five questions you should ask an event or meeting organiser when you are asked to speak.
1, How many delegates?
Smaller groups will interrupt you as you speak and play havoc with your timings and flow. As soon as you get above 20 people, this is rarely a problem. If you are presenting to a small group, you can use this to your advantage and can convert the presentation into more of a guided conversation.
2, Whats the Age Range?
Age gives you a hint as to the cultural references that you can make. 80s film references will not make sense with a group of 16-25-year-olds.
3, Whats the Gender Split?
It's easy to fall into the trap of only presenting from a single gender perspective. I use this as a reminder to check my content for unconscious bias.
4, Who is talking before and after?
Researching the other speakers and talking to them beforehand gives you an opportunity to find hooks into their content, to reinforce points they have made and create a thread between all of the talks.
5, How long do you need me to talk?
If you don't know the length of the talk, then you can't efficiently prepare.