Configure the My Items search by navigating to Setup > End-User Interface, and clicking the Customize button under Setup My Items.

This gives you a menu of Tables with default My Item searches already defined. Click the Edit icon to change the default My Items search or view for any of these tables. Create a new default search by clicking New, selecting a table, and selecting a saved search from the list of those saved to the table. You can also specify which view to use by default when viewing this table under My Items.

Customize the content and field placement for records and their input forms via Setup > Tables, select the Table to edit, go to the Layout tab, and toggle to the End User Interface view.