I have loads of tips but it's easier for me to answer questions and to comment on statements since it's a very wide field. I had posted up a ton of tips in another thread but I'm not sure what its title was.
I guess, long story short, my main advice is to be 100% honest and to understand than an interview is not just them interviewing you but the other way around as well. You're going there to find out whether or not it's the right job and environment for you.
People treat interviews like a test; like a school exam where they're expected to know the right answer. And, when people don't know the right answer, they often feel pressured to make something up on the spot to be able to deliver the right answer.
So, when they ask you questions, answer them honestly. Don't tell them what they want to hear, tell them what you really believe. If you don't know the answer to a question, simply tell them that. They'll either offer to reformulate the question or they'll move on to another question.
They can smell BS a mile away, so there's no point to making shit up. And what is the point of giving them the answers they want (rather than your real answers) if that will just wind up putting you in a job where your employer thinks you're something you're not? Eventually they'll figure it out and they'll regret their decision to hire you. Either that or YOU'LL regret your decision when you realize that, by giving fake or dishonest answers that weren't really how you felt, you now find yourself in a job or an environment that isn't really suited to your personality.
Another thing I would suggest is to back up your answers or statements with evidence.
If you tell them something like
"I'm a real team player", you need to back it up with
"for example, here is a while bunch of team player stuff I've done that proves that I'm a team player". Otherwise, the recruiter / interviewer just thinks that you're talking out of your ass and they'll ask a follow-up question like
"What makes you think you're a team player? Can you give me an example of a team situation where you demonstrated your teamwork skills? How would your last boss / team describe that you were a good team player?".
A recruiter / interviewer that doesn't ask these types of questions isn't doing his job. These are the questions that really determine if your answers / statements are based in reality or are a lot of hot air.
You can make a strong impression by pre-emptively answering these follow-up questions like I suggested above.
Last thing (for now): If, in the job posting / description, there's a requirement that you don't quite meet, don't freak out. Your were called to the interview for a reason. What you need to do is prepare some kind of counter-weight to overshadow the fact that you don't meet that requirement. So, let's say the job requires Photoshop experience and you don't have any Photoshop experience. You KNOW that they're going to ask you about it, so prepare ahead of time. Get ready to list them all the software SIMILAR to Photoshop that you've used. Prepare some real-life examples of how you're a fast learner so that you can explain to them that you'Re confident that you'll quickly learn Photoshop if needed. Go get some books about Photoshop and read some articles about it. Go on youtube and watch some demos. Download a demo and play around with it. That way, when they ask you "Do you have Photoshop experience" you can honestly tell them that you don't but that you've used aaaaaaaaaaaaaaaall these other similar softwares, that you're interested in learning about it, that you've played with the demo, that you understand basic functions, that you've installed it on your computer and are reading books and articles to expand your knowledge about it, etc. You then explain to them, using a real-life examples to back up your statement, that you're a very fast learner and that you're confident that you could get comfortable with it in a short period of time.
Boom.
If you were gold everywhere else, they'll appreciate your honesty and they'll be impressed by the steps you took to fill this knowledge gap.
Anyway, post up some questions or statements that you want to run by me and I'll gladly let you know what I think based on my experience.
We can even start a thread specifically for this, if you like.
