Ask Questions

Throughout

Ask your audience questions throughout your presentation to make it a more interactive experience for them. They'll be more willing to pay closer attention and you as a presenter can use questions as an opportunity to reinforce certain key messages.
Asking questions also breaks up your presentation and the need for you to speak the whole time. An audience may grow tired of your voice, so it's important they hear someone else's to mentally have their ears focus. With different people speaking, the audience will work harder to gather all of the information making their brains more active and apt to learning.
Throughout your presentation, let your audience ask you questions, too. Don't make them wait until the end to ask you what's on their mind because they'll feel confined and intimidated. Take time to pause and make sure there are no questions so you leave no stone unturned.
Here are the best types of questions to ask:
 
#1: Probing - finding out what your audience knows
#2: Rhetorical - letting your audience think about something
#3: Leading - guiding an audience member in to answers that support a key message
#4: Statistical - gaging the number of people who feel a certain way
#5: Ask & Answered - saying a question, but providing the answer yourself