Customize the Record Details page layout. You can add required fields or hide the unwanted fields, reorder the fields, create delete sections, mark fields as mandatory and change to 1 column or 2 column layout.
Change the order of the Related Lists such as the Attachments, Open Activities, Closed Activities, etc., for records in each module. Show or hide some of the related lists as per the organization's business requirements.
Organize tabs in such a way that only the relevant tabs are visible for use and the unwanted tabs are hidden. You can also rename the tabs based on your business domain.
Add custom fields of various types such as text, lookup, pick list, currency, autonumber, check box, etc. Formula fields can be created to populate dynamically calculated data based on the values returned from other standard or custom fields.
Create custom list views to filter records based on a given criteria. This will help you sort out the required records quickly and perform all the necessary operations on the records.