It may not be helpful for all situations, but in a lot of cases it would be very helpful if you get feedback from your audience about your presentation. Especially if you are giving multiple of the same sessions of a certain presentation. In that case you can learn from the feedback of the first session and apply this knowledge to further improve the following sessions.
Getting feedback about your presentation can be done in various different ways. You could hand out a paper feedback form or use on online survey form to get feedback about your presentation and suggestions for improvement. You could also just ask some individuals after your presentation about their feedback. Take advantage of the feedback received and use any meaningful feedback to further improve your presentation skills.