A tool that is for sure not used enough is fg / bg.
Example: Did you ever start editing a file and suddenly remembered that you needed to copy the values of the previous command? Well this take care of this problem and many others!
First of all, executing a command / job in background when in a shell is as simple as adding an “&” at the end of the command:
watch -d ls -l &
Another way to do this is by using the “bg” command, or by pressing “CTRL+Z”:
watch -d ls -l bg
In order to see all background running jobs use the “jobs” command:
jobs  + suspended (signal) nano ca.crt
Where “%1” is the number of the job. Using this syntax you can also kill jobs:
This is a very simple feature which can make your live easier if you learn to use it.