For a better desktop integration and keybinding from your Desktop environment, you can add custom Action to ksnip's desktop file.

Copy .desktop file from system to user:
$ cp /usr/share/applications/org.ksnip.ksnip.desktop ~/.local/share/applications/

Edit user file (~/.local/share/applications/org.ksnip.ksnip.desktop) and add unique name for the custom action in the Actions= field of the .desktop file and add the new action to the end of the user .desktop file:

...
Actions=Area;LastArea;FullScreen;Window;<NewActionName>;
...
[Desktop Action <NewActionName>]
Exec=ksnip <option to execute>
Icon=ksnip
Name=<Descriptive name of the action>

Example: Add a custom Full Screen Screenshot with delay:

...
Actions=Area;LastArea;FullScreen;Window;DelayedFullScreen;
...
[Desktop Action DelayedFullScreen]
Exec=ksnip -m -d 3
Icon=ksnip
Name=Delayed FullScreen Screenshot