[xb]

This is a good list of things to avoid when presenting. I'd like to add another that I've commonly seen:

Don't give up control of the presentation until it is time for questions.

Sometimes people will butt in with questions, and you should answer them quickly and minimally. I've often seen this kind of thing fluster a presenter, and sometimes the presenter will say "okay, is there anything else? any other questions? " as if to invite more interruptions. This is a mistake, you should quickly address the person who interrupted and then get back into your flow without allowing others the chance to also interrupt.

Another one, that maybe only I am bothered by, is don't start every single answer with "That's a good question..."

[nekopa]

This really depends on the presentation. Of course, you should be in control of the presentation, and let your audience know wether or not they can ask questions at any time, or at the end, or, if you've designed a well structured presentation, take questions at the end of each 'part' of your presentation.

The reason why it depends is if you're presenting something complex, say A and B and C, and if understanding B requires understanding A, and understanding C requires understanding A and B there is nothing worse than reaching the end of the presentation and the first question is 'What exactly did you mean by A?' and a lot of nodding heads. That means no one got two thirds of your presentation.

I've been teaching presentation skills for about a decade, and I've seen the above scenario plenty of times, mainly in legal presentations, but also in tech and sales presentations.