While I have always been extremely good at answering questions after presentations, I've often struggled with the "talking part". I generally preferred speaking one-to-one rather than in groups.
Some speakers don't seem to be bothered if the audience disengages, but I usually notice immediately. I've given great presentations at points but failed to speak the language of the audience in others completely. Knowing the audience - their language, their understanding - is crucial to giving thrilling presentations.
Equally important as speaking for the audience, however, is the question of why we as the speakers care - both about the subject as well as about the audience. This is not always obvious and needs thorough reflection and oftentimes courage. However, it's the essence to create a bond between us and the audience.
While I do think it helps to structure the content properly, demonstrate topic authority, use good body language, regularly make eye contact, talk slowly and pause frequently, it is more about the first two things. If we understand the audience and have a clear "why" - both about the subject, as well as about the audience - the rest comes naturally.
As with anything else, practice makes perfect. Particularly with today's social media channels, it is easier than ever to practice our presentation skills.