Here are some tips for interview.

HR Interview: The main objective of this interview is to get the technical interview or invited to an in-person interview.This interview is to determine the person's personality and team work.Warm up your voice and vocal cord---it may help to make you sound more confident, firm and pleasant.
Your voice tells many things about you.

DOs:

Getting ready for the interview:
Go to the bathroom before the appointment time in case the interview lasts longer than you expect.
Drink just plain cold water
If you use a hand set phone, make sure you have charged it properly.
Have your resume, paper, pen, and a glass of water handy
Take the call in a quiet area of the house---no kids, vehicles' sound pollution, no dogs, or any other distractions.
Be on time to show that you respect and value the interview appointment
Make sure you do not have another appointment close to the interview---incase the interviewer needs more time.
Read your resume thoroughly to explain your professional or projects' experience
Be prepared to give a positive two or three minute summary of your professional career.
If you did not understand the question, ask him/ her to repeat the question.
Be sincere.
Be enthusiastic.Speak confidently, clearly and slowly.
Ask the interviewer about the client location, project duration, etc.
Ask the interviewer at the end of the conversation where you stand and what the next step is.

Don't:
When you are on the phone, if you don't understand the question, don't pretend that you did. Ask them to repeat the question.
Do not feel nervous.
Don't sound phony.
If you cannot answer certain questions, admit to the interviewer frankly and offer to do more research on the subject and that you think you can get an answer soon.
If you don't know, simply say that you don't know. Be careful not to misrepresent the information or lie to the interviewer. Trying to cover up the truth only makes things worse.
Try to avoid using cell phones. Your client may not hear you properly.


Technical Interview: The goal of technical interview is to know about your technical skill set.

Dos:
Follow HR Interview Tips PLUS ....
Do your homework and practice answering some standard interview questions.
Review your resume and work experience/ history.
Interviewer may ask more questions about their project requirements or your primary skill set. Be ready on these two things before the interview.
If you don't know the answers, you can request the interviewer for answer.

Don't:
Don't try to evade an answer. If you don't know the answer, tell the interviewer you will find out the answer and call back.
Do not negotiate for the salary with technical interviewer.


After the Interview: If you are answered to all the questions asked by technical interviewer, note down all the unknown questions and get the answers to them.