Parameters need to configure for creating a new Oracle Database

The following is the parameter you need to take care of before delivering the database to the production environment to avoid future downtime.
Because in the production environment, once it is live, you need to change this parameter you need to bounce the database. In a Critical environment, you never ignore this parameter

Following parameters needs to consider while installing the New Oracle Database for production:

DB_FILES = (default 200 recommended 1000)
Set of maximum number of files in a database in the future you need to add more data files in the database. Handle error ORA-00059: maximum number of DB_FILES exceeded
PROCESSES = (default 150 recommended 600)
Set the maximum number of processes that can be started by instance. Handle error ORA-00020: maximum number of processes (%s) exceeded
SESSIONS = (default 172 )
It automatically set from the processes parameter when you change the processes parameter with alter system command. Handle error ORA-00018.The maximum number of sessions exceeded
TRANSACTIONS = default 189
It automatically changes when you configure the processes parameter
SESSION_CACHED_CURSORS = default 50 increase to 300
In a session, you can open a maximum number of cursors.
UNDO_RETENTION = default 900
Please increase the undo retention to 1800, it will increase performance and overcome the ORA-01555 Snapshot Too Old error in the alert log.
SMTP_OUT_SERVER =
If you need to configure something from mail in the future then setup the parameter in advance.
OPEN_CURSORS = 300 default
OPEN_CURSORS specifies the maximum number of open cursors (handles to private SQL areas) a session can have at once and overcome with error ORA-01000: maximum open cursors exceeded
AUDIT_TRAIL = NONE
Check the audit trail parameter by default it is set to DB level. If you need the audit then remain enabled otherwise disable it in advance.

Memory parameter
In Oracle, we have 3 major memory components:

MEMORY TARGET is that component that manages all other component means SGA + PGA. It manages according to run-time data basis. It is the best method. you can set in with two following parameters.
If you set a memory target then always keep MEMORY_MAX_TARGET with some greater value so that you don’t need to restart the database in the future if you need to add more memory in MEMORY_TARGET.

MEMORY_TARGET
Actual memory consumed by Oracle instance for its processes.
MEMORY_MAX_TARGET
Always set a greater value to the memory_target parameter. So, in the future, you can increase the memory target without restarting the database.

SGA Target has other components like a shared pool, large pool, java pool, db cache, etc. It manages the size of all the components in run time as needed.

SGA_TARGET
SGA_TARGET specifies the total size of all SGA components.
SGA_MAX_SIZE
SGA MAX SIZE is set greater value than SGA TARGET Parameter, So in the future, you can increase SGA size without restarting the database.

PGA_AGGREGATE_TARGET
PGA_AGGREGATE_TARGET specifies the target aggregate PGA memory available to all server processes attached to the instance.