Apart from literal values, you can set an instance as a default value of an attribute.
Enumeration items can be set as default values of attributes. After setting an enumeration item as a default value, it will be referenced - so if the item will be renamed, the changed name will be used for all references of the item.
You do not need to change visibility of the class attributes (or operations) one by one. You may select multiple attributes (or operations) and then perform the desired action.
If you have two classes connected by association you may want to add attributes representing the association roles. This tutorial shows how to do it in just a click.
There are many options how to set attribute type. You may type it, set it in the Properties dialog or drag another element from your project and set it as the type. The last option is described in this tutorial.
UML Profile Diagram describes and defines extensions to UML language. The extension mechanism allows you to adjust the language to a specific domain or platform. The extensions are defined via stereotypes.
UML timing diagram is focused mainly on time, it shows the changes of classifiers in time depicted on a timeline. The timelines are stacked vertically, the time increases from left to right.
UML Interaction Overview Diagram provides a high-level view on interactions in a system or a subsystem. It depicts the flow in similar way as an activity diagram, but instead of action nodes it uses other interaction diagrams and interaction references.
Composite structure diagram shows the internal structure of a classifier, its parts and ports via which it communicates with the environment. It models collaborations where each element has its defined role.
UML Deployment Diagram depicts deployment of artifacts on nodes. It is used for showing the placements of artifacts (software, system, module, etc.) on physical nodes (hardware, server, database, etc.) and the relationships between particular parts of the solution.
Component diagram offers a view on a complex system. It depicts the interfaces provided and/or required by the parts of system and the relationships between the parts. The parts are represented by components and other artifacts.
UML Package Diagram shows dependencies between the packages in the model. It depicts the structure and organization of project in the large scale.
Object diagram is a structural UML diagram. It describes a system or its part at a specific time. It models instances, their values and relationships. It may be use to show examples of data structures.
State machine diagram describes states of en entity (device, process, program, software, module, etc.) and transitions between the states. Conditions specifies when a transition from a state to another state may be used.
UML Communication Diagram shows interactions in form of messages between objects and parts, which are represented by lifelines. Communication Diagram is a modified form of UML Sequence Diagram, but unlike it, its elements do not have to be ordered horizontally and may have any position in the diagram.
Activity diagram is a behavior diagram, which shows a scenario using a flow of actions. It models a sequence of actions, decisions based on conditions, concurrent branches and various cycles.
Sequence diagram models communication among objects in sequential order. It shows object, classes and actors involved in the scenario and exact order of messages. It consists of vertical lines which belong to lifelines and horizontal lines of messages.
Use case diagram consists of use cases, actors and relationships among them. It presents a user interaction with the system and defines the specifications of use cases.
Class Diagram is a static structure diagram which describes the structure of a system by showing its classes with their attributes and operations, and the relationships among objects.