Interviewing is a very specific muscle. You should try and do as many as you can. It’s also something you should regularly practice, even if you have a job you love and never want to leave. I’d say every year or two, just go and interview at a half dozen companies for roles that could be interesting to you.
I’ve just been through several rounds of interviews with different companies for a tech role. You want to build a brand and learn to communicate it to others. This doesn’t mean you need to write a laundry list of skills that you’ve obtained but rather define who you are and practice explaining that to strangers.
Nothing can prepare you for an interview scenario except and interviews. I’ve been in customer facing roles as well as being the interviewer and the only thing they have in common with being interviewed is that you’re sharing a table with someone else.