I list here some non-obvious Linux tips and tricks I found useful.

1. Changing volume step in Xfce

When you roll the mouse over the volume icon or press the keyboard media keys, the volume changes, and the default step size is 5. It is not obvious, but you can change this in the the Xfce Settings Manager.

Go to the Settings Editor > xfce4-panel, and find the plugin for the volume icon (the name will be pulseaudio). Then add the option 'volume-step' with a Int entry, and the value corresponding to the step you want. Done!

In my case, the setting was it was like this:

2. Autocd

The terminal command cd changes directory. You can set autocd so you just type the name of the directory to change to it. Just add the command shopt -s autocd to the file ~/.bashrc.

3. Add PPA Key in Debian

Go to the PPA page and find the key fingerprint. Then run:

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:8 0 --recv-keys [fingerprint]

(replacing [fingerprint] with the provided fingerprint)

4. Creating a bootable USB

sudo dd if=[file] of=[destiny] bs=1M status=progress