Think of having someone as a CRITICAL COLLEAGUE offer you feedback on your presentations. Ask for recognition of your strengths and constructive criticism on things you might improve in future.
The presentation challenge is everlasting. We never reach the pinnacle. If we feel we have made it, with nothing left to learn, our slide into the area of lesser effectiveness begins immediately.
Encourage those in your workplaces, to consider speech and speaking development. So many people are frightened of dealing with the public because they lack communications confidence. Help them up.