Hello
The ones mentioned above are based on personal experiences.
For a standard SAP system installation I can add tasks like SLD configuration, Solution Manager plug.
The most important thing you need to follow is the post installation activities mentioned in the installation guide provided by SAP.
https://websmp208.sap-ag.de/~sapidb/011000358700000877522012E
Rest is done based on requirements.
Regards
RB