Boring answer but really the main thing is to just get as much practice as possible in the kinds of questions they're going to ask you. It's good if you can get specific feedback so in that sense one of the online interview practice sites where they pair you with someone might be beneficial than just practicing a bunch of leetcode. As for getting past the anxiety you might feel on interview day realize that it is normal and have the mindset that you're going to approach the problem as more of a collaboration with your interviewer where you discuss your approach and write some code rather than just a strict evaluation. Most people really do want to help you get through it from what I've gathered so it pays to leverage them by asking questions and checking to see if they think you're on the right track.
