Maximizing opportunities to be admitted in top schools I did a modest undergraduate in Information Systems (3/4) and good master's in CS (3.4/4). I've PhD acceptance from a good school in Canada. However, I still need to go to top school , or at least a well-known school, in US. 

I am planning to apply to top schools in CS next year (since deadlines already passed). I have done some research and got some papers accepted at good conferences. Beside getting good scores in GRE, what should I do to be well-prepared for the next year? 

I am fully sponsored student by my government, how will this affect the admit decision?
Your approach is wrong and will be a hindrance in maximizing your chances for acceptance. No school wants to accept someone who only wants to go to their school because of its ranking. You need to tailor your application to demonstrate why you want to go to the particular school. Once you have identified some schools/supervisors, ideally one of your recommendation writers can introduce you. You then need to build on that relationship. Talk to them about how your work fits in with their past and current work. As your relationship with the potential supervisors builds, figure out how they fit into the department. They will likely have the inside knowledge needed for writing a really good application.