It really depends on the school that you are posted to and the HOD whom you are working for. Generally, you need to show good attitude and willingness to work and contribute. By the end of the stint, you need to exhibit some skills in teaching and learning, depending on the school's direction. All these points have been mentioned in previous posts.

What I would like to add on is to open your eyes to the things that your school is doing. Does it go against logic? Does this job make you stressed out for no good reason? Does your HOD appreciate your willingness to work? Does your CT guide you properly?

If you do not like the experience in your school, it is very important to ask yourself what is it that you dislike. The management? Or what the job entails? It will be good to make friends in your ITP class, so that you can make comparisons. Because what your experience may not be representative of what other schools are doing.

Instead of thinking of how to increase your chances of getting into NIE, I feel that you should take this opportunity to think whether this is for you. Once you sign the bond, it will be a painful 3++ years for you.

(From someone who finished her untrained stint in 6 months. Contract school was great but currently suffering in her first posting - a different school. )