Using keyboard shortcuts in VirtualBox can significantly improve your workflow and overall performance. Here are some of the most useful shortcuts:

1. Host Key + Home: Show/hide the VirtualBox menu bar
2. Host Key + F: Switch to full-screen mode
3. Host Key + L: Switch to scaled mode
4. Host Key + C: Send CTRL+ALT+DEL to the guest OS
5. Host Key + P: Pause the virtual machine
6. Host Key + R: Reset the virtual machine
7. Host Key + S: Save the virtual machine state
8. Host Key + T: Take a snapshot
9. Host Key + Q: Close the virtual machine
10. CTRL + ALT + Backspace: Restart the X server (on Linux guests)

Note: The default Host Key is usually the right CTRL key, but this can be changed in VirtualBox settings.

Remember to familiarize yourself with these shortcuts gradually. With practice, they’ll become second nature and significantly speed up your VirtualBox operations.