This Article shows you How to Create/Add Manually an Application Launcher in the Main Applications Menu on Linux Mint 13 Maya Xfce.
The Process Require a Little Patience and a Minimal Skill to be Successfully Replicated.
And this Visual Guide includes the Basic Screenshots of All GUI Steps involved.
The Content give Focus Only to the Essentials Instructions and Commands to make it Easier to Follow.
We Will Limit to Use the Categories Already Present Into the Applications Menu Without to Add Any New One.
Open a Terminal Window
Open with Gedit as SuperUser an Existing Launcher on Directory:
/usr/share/applications
For Example Open the Firefox Launcher:
sudo gedit /usr/share/applications/firefox.desktop
There you Find a Trace of what you Need to Transform for to Obtain your New Launcher.
Modify at Least:
Name: The Name
Comment: The Description
Exec: The Command
The Icon:
The Icon need to be of SVG (Scalable-Vector-Graphics) 48×48 type and located Into the Directory: /usr/share/icons/hicolor/scalable/apps
How to Easy Find/Search Files/Directories/Images on Linux:
Set the Category.
The Setup Make Use of Keywords that Map to the Correspondent Categories.
The Category’s Keywords to Use are those Below:
Network for Network Category
AudioVideo for Multimedia Category
Utility for Accessories Category
Office for Office Category
Settings for Settings Category
System for System Category
Clean the Remaining Trash Chunks.
Save As New Launcher
newapplication.desktop
Find your Newly Created Application Launcher 
Here Below Link to Article with Tutorial 4 Locating Files/Icons Under Linux.
Tags: App Launcher, Application Launcher, Guide, How-to, Linux, Linux Desktop, Linux Mint, linux Mint 13 Xfce, Tutorial, Xfce