Crocus offers a bunch of convenient shortcut keys that can help you work faster.
While editing a CamelCased name you can move your cursor quickly to name's next part by using Ctrl+← or Ctrl+→.
It also applies to selecting (Ctrl+Shift+← or Ctrl+Shift+→) and deleting text (Ctrl+Del and Ctrl+Backspace).
You can select items to be content of added package. Simply choose package tool and select some boxes with your mouse.

Sometimes it's convenient to minimize a box (e.g. class or package) after some of its content has been removed. You can do it automatically by double-clicking boxe’s resizer.

Very often methods don't take any arguments. In that case after typing method's name it's convenient to jump right to return value edit, without need to stop at arguments. You can do that by typing : (colon).

There are three ways of quick navigation:
Project explorer provides you a hierarchic view on your diagram. You can toggle show it by clicking "P" icon in toolbar, or by hitting L on your keyboard. You can also drag&drop project explorer to a more convenient place.
Got lost in your diagram? Locate your box on the diagram by double-clicking it in project explorer, clicking locate box in context menu or pressing Ctrl+F
You can select more than one item by clicking on them with Ctrl key pressed. You can also unselect items that way.
Need to print or paste your diagram into some other document? Use export to image feature in main menu.