Making an excellent impression when interacting with another person is something most people desire (in particular when seeking work).
There are some fantastic tips/tools that can really make a difference. Did you know that within 4 seconds you will decide if you like the other person on not!
Not much time, ahh, perhaps enough time for a hand shake and some visible evidence and observations of body language and tone............ then it’s a yay or nay!
You may be surprised to find that how you communicate consists of:

55% body language
38% tone
7% words

So............ if you are excellently turned out but do not give any eye contact, your body/shoulders are hunched, your hand shake weak and your tone fast and high pitched you are not onto a winner (and that's before you even get into any interview questions!)

How would it be to be REALLY prepared and feel really confident?

Well first things first. Questions to ask yourself before you even get into the above:
 
1. Do you REALLY want the job?  5 (if the answer is on a scale of 1 -10. 1 being no)
It will be picked up in your body language if its 5 or less, so aim for higher.

2. Have you done the research about the job? What this entails is learning a bit about the values of the company. Do they have what you want (ask them), it’s not all about them wanting you.
 
The obvious things of being well presented - hair, nails, personal hygiene and smart appropriate cloths.

The less obvious - Make sure you have had an early, (alcohol free) night before, had a recent meal and drank plenty of water before the interview.  Make sure you don't rush your words and, most of all, SMILE and be passionate (I got a job once I had no experience in but was so passionate that I could do the work!)
 
Write down before you go what you personally have to offer them .......... why should they pick you?

Be prepared to look at what you are good at (if you don't know ask some close friend and family).

Also remember if you don't get the job it’s not PERSONAL! I went for 8 Practice Nurse jobs and never even got as far as an Interview! 9TH time lucky.

Communication is not just to others it’s too your self, do you listen to your body and take care of it? Do you eat healthily, get plenty of rest, have an equal amount of fun as well as work? Do you worry about things that you have no control over? There are many ways to communicate with your self, one way I have been using for 7 years is 30 minutes what I call "quiet time" I just sit early in the mornings for 30 minutes before my day starts, close my eyes and breath!

It’s really fantastic how my body communicates with me, I notice if I am tired or lonely or upset etc and then am able to act on the information. Often ideas will come into my head which I can work on.

Some people do yoga, meditation, pilates, go for relaxing walks outside in nature. Whatever it takes.

So.................. These are some useful tips that WORK. How do I know? Because I practice what I preach. I DON'T JUST TALK THE TALK I WALK THE WALK.