Hi Sirisha,
When conducting Interview, you should observe the candidate's behavior from the beginning that is how is he/she entering into the room, was he/she humble and take the step ahead to greet people, sitting posture etc
When you start interacting with him/her, look at in his/her eyes and be a good listener...... you may find it difficult to guage a person in the initial stages but the time passes by i am sure you would get this trick of understanding people's behavior which is very much required in our profession.......
Put up questions mostly on "How" part rather "What" and when you ask these type of questions the candidate needs to give the detailed answer as to how did he/she achieved the set milestone and try as much as possible deep dive into it to know more and more details by which you shall be able to know whether the candidate is a team member, gel with people, customer centric, result oriented, etc etc
Hope this will help you to some extent.......