There's a million articles on interviews, here is my two cents.
Now, I am only a software engineer, so don't talk my word as gospel or anything. But, I've done a dozen interviews in my life, and I've learned a few things about how to do them better, most of these tips I am sure you have heard before, but I still don't see people actually do this, so here are my two cents.
Confidence. Now is a great time, to be a bit of an arrogant prick, who is awesome? You are. You deserves the job, you do, absolutely! The companies need you, not the other way around, they wouldn't be paying company time on interviewing you if they thought you sucked.
Tell me about yourself This question, without fail, gets asked, without fail, on basically every interview. It's also, a super difficult one to BS, you know why? Because it is designed to trick you. Here is what they meant to ask you. Why are you specifically a good fit for this job? How does your experience line up with our company? If you didn't do your research ahead of time, your gonna tell them crap they don't want to hear. Do your research, figure out why your a good fit, and tell them why you are a good fit, first thing.
the three try rule If you do get past the soft interview, and you get to the technical part, and they ask you some technical questions, if you don't know, just freaking give it a go. They ask, what is dynamic polymorphic behavior in like... Java or C++ just freaking bs. Oh, dynamic polymorphic behavior is a really flexible way to create re-usable code that functions well and scales nicely. If they raise an eye at you, like, don't flinch, keep your cool. Now, you can totally do this BS'ing two times, but like... 3rd strike your out. You should absolutely BS on questions you don't know, twice. Then on the 3rd one, just say, I don't know, I don't think I have done that one yet, what is it? Pivot your strategy. Try to get them to talk about the thing you don't know. You want to learn right? Now's a great time. You know what people people like to do? Talk about crap that they already know. You know what people do when they are happy? They like you.
Follow up You already spent an hour interviewing... an hour preparing, got your hopes up... but it's been two days and you haven't heard anything back from them. You know what you do then? Call them. E-mail them. Let them know you are still interested, e-mail them saying you want to wait for them, but you have other offers that are pressing you for time, and you haven't heard back from them. Put the ball in their court, pressure them. Nobody is going to give you a job, you have to take it.
Anyways, just some advice I have given in the past. Best of luck out there!