Good planning is actually how you can ensure you will have enough time to do a good job and reserve some space for creativity.
Before going deep into detailed planning, first of all define:
While planning, consider how much time you’ll need for:
- concept evaluation,
- detailing your design,
- design evaluation,
- preparing deliverables.
Go in small steps. Iterate.
It is important:
- plan to perform several design iterations during the process in order to refine your design,
- plan to reuse the results from the previous steps and iterations in the following steps and document key decisions.
If different steps are executed by different teams ensure sharing of the information.
In reality things rarely go according to plan but since you have it, you can adjust estimations, foresee consequences and proceed. Do not forget to communicate the plan adjustments and consequences to the project team and stakeholders.
Do not forget to communicate.