Altium Designer Notes

1.  Q --> change to imperial to mm or reverse is true
2. TAB --> open properities panel
3. After selecting the component, press the left key of the mouse and click the J+R character on your keyboard. This shortcut helps to which you select things and move to the center.  
4. CTRL+M --> Measurement , SHIFT+C clear measurements value view. 
5. Press G character to change grid size.
6. Place->Directives->No ERC for closing unused pins
7. ON/OFF  if you want to top line to "ON" a straight line, use this technique.
   

 

Note: when you need a specific shortcut about Altium Designer. please see this video for remembering something.