Explanation:

The best way to ensure the end-user experience when designing a new page layout for a custom object in Salesforce is to group similar fields using sections. Sections are UI components that allow you to organize fields into logical groups and provide headings and descriptions for each group. Sections help to improve the readability, scannability, and usability of the page layout by reducing the visual clutter and providing a clear structure and hierarchy for the information. Sections also help to align the page layout with the user’s mental model and expectations, as well as the business processes and workflows. [UX Designer Certification Prep: User Interface Design Principles], [UX Designer Certification Prep: Salesforce Design System]

Including all potentially useful fields is not a good way to ensure the end-user experience when designing a new page layout for a custom object in Salesforce, because it can create a crowded and overwhelming interface that is hard to navigate and understand. It can also increase the cognitive load and the scrolling effort for the user, as well as the maintenance cost for the designer. It is better to include only the essential and relevant fields that the user needs to perform their tasks and goals, and use other methods such as related lists, tabs, or modals to display additional information. [UX Designer Certification Prep: User Interface Design Principles], [UX Designer Certification Prep: Salesforce Design System]

Making field labels and API names identical is not a good way to ensure the end-user experience when designing a new page layout for a custom object in Salesforce, because it can create confusion and inconsistency for the user and the developer. Field labels are the text thatappear on the user interface to identify the fields, while API names are the unique identifiers that are used by the system and the code to reference the fields. Field labels and API names should be different, because they have different purposes and audiences. Field labels should be clear, concise, and descriptive, using natural language and proper capitalization, punctuation, and spacing. API names should be concise, unique, and consistent, using underscores and camel case to separate words. [UX Designer Certification Prep: User Interface Design Principles], [UX Designer Certification Prep: Salesforce Design System]

Marking all fields as required is not a good way to ensure the end-user experience when designing a new page layout for a custom object in Salesforce, because it can create frustration and annoyance for the user, as well as increase the error rate and the abandonment rate. Required fields are fields that the user must fill in before they can save or submit the record. Required fields should be used sparingly and only for the fields that are absolutely necessary for the system or the business logic. Marking all fields as required can make the user feel pressured and constrained, and force them to enter irrelevant or inaccurate data. It can also make the user miss the truly important fields, or give up on completing the record altogether. [UX Designer Certification Prep: User Interface Design Principles], [UX Designer Certification Prep: Salesforce Design System] References: [UX Designer Certification Prep: User Interface Design Principles], [UX Designer Certification Prep: Salesforce Design System]