kunzi,
My tips:
1- Practice Practice Practice - Answers to all the standard questions such as Why MBA?, Why MBA Now?, What are your near term/long term goals? Why Ivey? Practice with family/friends who know your professional background well so they can give you tips on ways to improve.
2 - If you are looking to switch careers (industry or job function) you will have to demonstrate a track record of actions you have taken to better assimilate with your target career. The best piece of advice I got early on is "Be a groupie within you target industry/career".
3 - Be ready to illustrate examples of leadership and initiative in your career thus far. As you provide these examples, the interviewer might stop you and probe you further on specific items. Use these "follow up" questions to add more colour, personality and personal differentiators as best you can.
4 - Have a clear understanding of what you bring to the program. Why will Ivey want to admit you? If you get in, how do you feel you can contribute to Ivey?
5 - One interesting question I got was based on some details on my career. But paraphrased the question would be "If you wake up tomorrow and you are the Executive Vice President at ABC Company, how would you address the slide in your company's performance?" Ivey is testing you to see if you are thinking about your own company from an executive's perspective.
Finally a few salient points:
A - The Ivey admissions team is very thorough; but most importantly they are very experienced. Don't embellish or "stretch" your profile. They have interviewed hundreds of students every year and they will see right through that.
B - When asked a question - get to the point quickly. I personally had to practice this a fair bit because I tend to provide too much detail when I answer questions. If they are interested in learning more - you will be probed and poked for more detail. That's when you open the floodgates. =)
C - Be confident (which will only come with practice) and engaging. Smile and show some personality - but steer clear of being a comedian or acting arrogant. Its a delicate balance - but this is more about who you are - something I don't think can be practiced.
Hope that helps. Good luck on your interview! Is Ivey your first choice?