These are the bits of Salesforce I find drudgery and therefore avoid doing them, but they do make a difference to the end user. Every SF Admin needs to know about these and set them up in a clear and consistent way. 

Views

See Views

• Consistency of the fields in the views
• Then adding new fields to specific views as they are needed
• Views for each Record Type at least
• View permissions - setting up public groups and giving access only to specific groups. 

View Layouts

• Recent Items Views
• Search views

Page Layouts

See Rules for Page Layouts and Page Layouts

• Complete consistency in page layouts
• Mini Page Layouts for each page layout 
  • And keeping them consistent
  • But with specific fields where necessary
  • Try to keep them the same as views
• Consistency in Naming (especially for different profiles or different pages). 

Related Lists

• Consistent related lists

• Sorting
• Correct fields

Compact Layouts

If using Salesforce Mobile App

• And keeping them consistent
• But with specific fields where necessary
• Try to keep them the same as views and mini layouts

Search Layouts

See Search

• Adding them to all objects that need it. 

Objects

Fields

• Consistency in naming - eg
  • no Underscores
  • Shortened names eg Num