I generally read through my resume and prepare extended blurbs about the projects/responsibilities I've written about - after all, that's really all they'll know about me at first.

Then I think of more detailed things throughout my career so far that wouldn't be resume-worth, but that I'm proud of or learned from or whatever. Just to have a bit of a script for that side of things.

I make sure I've got good enough answers for the basic interview questions: biggest strength, weakness, hobbies, projects outside of work (and why I don't do them), best project, worst project and why, etc.

I try to have 2-3 questions to ask them at the end. Sometimes I don't really have many good ones, so I make a note to make some during the interview itself - asking about tech stack details is usually a good springboard. And I genuinely will make a note to myself to remember that because I know that I can flip into autopilot and not be very chatty.

The rest for me honestly is just rehearsing that basic script enough to let it flow casually so that I can spend my energy on listening and interacting with the interviewers (and being in a good headspace for any technical questions that pop up).

When I've not done that step, because of the nerves from being on the spot and with new people, I tend to come off kinda stuttery and unsure of myself. And it's all about confidence, babyyyyyyyy

*Edit: this is interviewing for a job where I'm comfortable with the roles and responsibilities. If I wasn't as confident in my abilities, I'd also spend significant time doing general studying on those parts. But I'd also be ready to say that I didn't know something yet, but I have a track record for being a fast learner, such as when I blah blah blah...