Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
One of the most annoying things about Linux is mime types for files. In KDE, when you right-click a file, and then select Open With, a little fly-out menu appears. You will see a couple of options in this menu. If none of them are the right one, you can click on Other. Another dialog box opens, laughing at you, daring you to attempt to locate the intended application yourself, challenging you to a battle of wits. At that point, you need to know the precise location of the program to open it with.
For example, if I have a .kino file that I would like to open with KINO and not Kate, I can put some magical fairy dust into that box, making it find the app itself. All you have to do is put in the following: