What to consider when presenting without PowerPoint? (I hope this question is not off-topic, if it is, maybe you can suggest how to make it on-topic?)

I am in the biological sciences and I'd like to present my research (in front of colleagues who know about our research area but not specifically about my topic) without using PowerPoint (or slides created by a similar tool). I have about 30 minutes for the presentation which is supposed to be the basis for the subsequent discussion of my work.

There is the possibility to use a whiteboard and/or flip chart. And of course I could provide my colleagues with some printed material before the presentation starts.

My motivation for this kind of presentation is simply to move away from the expected and conventional PowerPoint-presentation and try out some different techniques.

What should I consider to make it easier for my audience to follow, and what should I avoid?
I think you are right to want to avoid PP or similar. Slides can help a presentation but can lead to horrors such as the presenter standing with back to the audience reading the words on the slides.

I have a number of thoughts based on my own experience over many years of public speaking with and without slides:

If you have no slides then the audience's attention is going to be on you. How confident are that you can hold their attention? What is your speaking voice like? Can you modulate it to vary the tone? Do you have any verbal tics that they will find irritating? You could practice in front of a trusted friend who must be honest with you about such things.

You must avoid reading aloud from notes. Notes that are just headlines are good. If you can manage without notes that would be great.

If you use the flipchart then avoid putting too many, or even any words on it: just visual images. If you circulate a paper in advance do you think they will read it before the presentation? If they don't then they will have their heads down reading when you want them looking at you and listening intently.

Good luck.