ABAP CDS views guidelines

Hi,

Are there any guidelines on what should be coded in basic, composite and consumption views.

In other words, should one put only one table without filters in a basic view or can one put more in it, like a join/association with a text table eg combining an HRP-table with the corresponding HRT-table?

Or should all join/associations happen in composite views or do only this for a certain subject eg all infotypes for an employee?

What should be put in the consumption view then?

Many thanks in advance.

Eddy