1. Proper planning of a project before the project even begins.  A complex project can be broken into smaller phases making it easier to estimate.  This makes it easier to solicit input from those who will be performing the work or other seasoned estimator's in the organization.  This also allows one to set milestones for the completion of each phase.
2. Reviewing the progress of the project against the milestones set.  This allows adjustments to be made during the course of a project to ensure the overall schedule is met on time.
3. Developing a knowledge base through investigating the causes behind a project's failure to reach a milestone.  This makes future estimating easier, as well as providing documentation of delays.

More information on each one of these techniques can be found on my helium article http://www.helium.com/tm/225201/delivering-project-essential-todays.

There was one point I didn't fully expand upon which I feel is equally important for project managers to be successful.  Sometimes we are faced with delays which we can not fully anticipate during the initial project scoping and estimating phase.  These delays could be increased regulations passed after a project was started, natural disasters, or changes requested by the customer.  Often times, it's very easy to overlook these delays and in an attempt to meet the project goals, we adjust resources upwards to meet the schedule.  However, many of the contracts allow for changes in completion time and fee when these items occur.  When we make these adjustments, we are providing value to our customer, and we should be compensated accordingly for the additional value provided.

I believe the concept of additional compensation for added value applies not only to organizations attempting to differentiate themselves, but also organizations which are competing on the basis of cost leadership.  Particularly when you consider cost leadership organizations which run very lean and have no room for a loss in profitability on a project.