The best option for improving the user experience of looking for and viewing commonly used reports is to update the Home page with access to commonly used reports. This way, the user can quickly access the reports they need without having to use the global search bar every time. This also follows the principle of designing for the user's goals and tasks, which is one of the learning objectives for the Salesforce User Experience Designer certification.[Design for the User's Goals and Tasks], [Change or Add Report Chart and Dashboard Components to Home Page]
https://trailhead.salesforce.com/en/content/learn/modules/ux-designer-certification-prep/design-for-the-users-goals-and-tasks

Voice is the overall personality of the design, while tone is the way that personality is expressed. Voice represents the core characteristics of a design, such as the values, attitude, and emotions it conveys. Tone is how those characteristics are expressed in the design, suchas the language, visuals, and other elements. For example, a design with a friendly voice might be expressed through warm colors, friendly imagery, and casual language. Salesforce has some great resources on voice and tone such as [1] and [2].
[1]https://www.salesforce.com/blog/2017/11/voice-tone-brand-personality.html[2]https://www.salesforce.com/blog/2018/10/voice-tone-brand-personality-ux.html

Card sorting is a technique that helps UX designers understand the mental model of users and how they organize information into categories. Card sorting involves giving users a set of cards, each with a piece of information or a feature, and asking them to sort them into groups that make sense to them. The designer can then analyze the results and identify patterns, similarities, and differences among the users' categorizations. Card sorting can help the designer suggest a suitable architecture for the new internal community, based on how the employees think about the site's content and functionality.Card sorting can be done in person or online, using tools like OptimalSort or UserZoom1.Reference:
[Salesforce Certified User Experience Designer Exam Guide], Section 2.1: Conduct user research
[UX Designer Certification Prep: User Research], Unit 3: User Research Methods
[Prepare for Your UX Designer Credential], Trailmix: User Research
[Card Sorting: A Definitive Guide]1

The two Salesforce features that should be suggested to improve the end-user experience are:
Favorite the often-used object. This feature allows the users to bookmark the object's tab and access it quickly from the Favorites menu in the header. This way, the users do not have to search for the object in the App Launcher or switch to a different app to use it.
Personalize the navigation bar. This feature allows the users to customize the navigation bar in their Lightning app by adding, removing, or reordering the items. This way, the users can add the object they often use to their navigation bar and access it easily from any page in the app.
1: Favorites in Lightning Experience
2: Personalize Your Navigation Bar

Personalized Navigation Tabs are a navigational feature that allows the users to customize the navigation bar of the Salesforce mobile app with the items that they use most frequently. Users can add, remove, and reorder the tabs in the navigation bar, and access them with a single tap. Users can also mark their favorite items with a star icon, and access them from the Favorites tab.Personalized Navigation Tabs can help Cloud Kicks (CK) employees to quickly access the apps, objects, and other items that they need in the Salesforce mobile app12 Console Navigation is a navigational feature that allows the users to work with multiple records and objects on a single screen in the Salesforce desktop app.Console Navigation is not available in the Salesforce mobile app, and it is not suitable for providing quick access to apps, objects, and other items3 Utility Bar is a navigational feature that allows the users to access common productivity tools, such as notes, history, or macros, from a fixed footer at the bottom of the Salesforce desktop app.Utility Bar is not available in the Salesforce mobile app, and it is not suitable for providing quick access to apps, objects, and other items4 Personalize Your Navigation Bar in the Salesforce Mobile App - Salesforce Help Personalize Your Navigation Bar in the Salesforce Mobile App Unit | Salesforce Trailhead Console Navigation - Salesforce Help Utility Bar - Salesforce Help