The considerations to be observed when creating object relationships are as follows:
Create the object relationships as a first step before you start to build the custom fields, page layouts, and any related list
The Related To entry cannot be modified after you have saved the object relationship
When you're planning to create a master-detail relationship on an object, be aware that it can only be created before the object contains record data
Clicking on Edit List Layout allows you to choose columns for the key views and lookups
The Standard Name field is required for all custom object-related lists and also for any page layouts