Resist the pressure to skimp on planning so you can start the work immediately. What time you spend up-front on planning will be repaid several times over in time saved later.
Understand the difference between the effort an activity takes and the duration of it.
Contingency is not poor management, but a realistic and essential component of a plan to account for the risk inherent in any task.
Focus on getting your plan complete more than worrying about estimates. A poor estimate will mean you may overrun on time, but a missed task may mean you cannot complete the work. (Read Chapter 5 for some important tasks that are easy to forget at planning time.)
Get the right team, as no matter how good a plan you have, without the right project team the work will not get done.
Planning software helps you present and manage your plan, it does not ensure your plan is any better.