Intellij Idea Keyboard Essentials
My first tip, let's start with typing.
Looking at the productivity guide (About -> Productivity Guide), here is what I use many times a day, might be helpful:
<kbd>Ctrl+W</kbd>, <kbd>Ctrl+Shift+W</kbd> - syntax aware selection - I think I do 95% keyboard selections with it. <br/>
<kbd>Ctrl+Space</kbd>, <kbd>Ctrl+Shift+Space</kbd> - you already know it!<br/>
<kbd>F4</kbd> - go to definition. A universal key which works in many places, in code, in a project tree.<br/>
<kbd>Ctrl+Alt+V</kbd> - I use it to save time typing the left part of declaration.<br/>
<kbd>Ctrl+/</kbd> - quick comment.<br/>
<kbd>Ctrl+N</kbd> - go to class.<br/>
<kbd>Ctrl+O</kbd> - override/implement methods.<br/>
<kbd>Ctrl+Q</kbd> - quick JavaDoc.<br/>
<kbd>Shift+F6</kbd> - rename.<br/>
<kbd>Ctrl+Shift+A</kbd> - search through all commands in menus.<br/>
Hope this saves you time with this IDE in which Java appears to be not verbose.