Apart from being confident in your work and experience, there are several other things that are considered for hiring, and People & Soft Skills is one of them. You can also make use of a Pre-interview checklist for the same.
As part of the Checklist, please note the following:
Print the Resume and the Job Description
As Mr. 007 says, Dress for Success with a Professional Hair Style
Practice both Technical and Behavioral Skills
Keep yourself Energetic on the Entire day of the Interview
Learn as much as you can, about the Employer
As part of the People & Soft Skills, please note the following:
Develop your Communication Skills like Listening, Keeping Patience,
Speak to the point
Your ability as a Team Player, is Tested thru Questions on Real Life Problem Scenarios
Pay Attention to Details, from Writing CV, to Presentation and Responses
Your ability to be a Critical Thinker, in times of Constraints is Tested thoroughly
Your Creative Thinking Ability is tested time and again, for Innovative Ideas
So, just being good Technically is Good, but have a Sound Soft Skills Exposure, plays 90% of the part, while Cracking Interview.