These job interview questions are pretty likely to come up. These should be the easy questions to answer, because you know they are likely to come and have time to prepare your best answers.

Get your hands on some kind of voice recording device. An answering machine, a mobile phone that
takes personal messages, a microphone plugged into a computer, whatever. Practice talking to it and
play it back. You might be surprised to find out what you hear.

It is a good idea to hold a professional manner during the interview. Don't go too far into ice mode though, look for eye contain and flash a smile every now and then. This is obviously dependant on the job situation and the vibe you are getting during the interview. Obviously if you want to be a (real) clown, you are going to be more in your face than if you are chasing a secretarial position.

Behavioural interview questions are the questions where they get you to explain how you would handle yourself in a given situation. The interviewer is trying to determine how you solve problems and whether this fits in with the role in question. The idea is that your previous behaviour will be similar to your future behaviour.

When answering job interview questions, don't be afraid to take a little time to come up with your best answer.
If a good answer doesn't immediately spring to mind, don't start waffling about the first thing
that springs to mind.