Talk about the application
An applicant for a planning permit is encouraged to discuss their initial plans with neighbours prior to lodging their application with council.
Permit applicants are not required to do this, but taking the time to talk to neighbours prior to lodging an application may allow you to consider and address any concerns they may have with the plans.
If a permit applicant approaches you, ask for a copy of the plans so you can think carefully about what is proposed and how you might be affected.
If you have concerns, suggest ways that the plans could be changed to address them. For example, it may be possible to retain a significant tree for shade and screening if the setback from the boundary is increased. The permit applicant might not agree to make these changes, but they are now aware of your concerns.