Whether you organize yourself through a to-do list or through google docs and calendars is not the issue. The issue is the fact that time is an expensive perishable resource that must be well used.
A to-do list is of course critical. Most people will prepare a lengthy daily to-do list that will never be completed in a week. Most only achieve 10% of the sought achievements.
Include time for rest and disturbances while planning. You cannot possibly shut out the world because you have become organized.
Plan wisely and realistically. The list should be prioritized and organized chronologically. Once you have your list in place, ensure that you stick to it. Do not allow side shows to derail the list (use reason).
Time is money. Use it to achieve the most.