Create your own menus and sub menus off the main menu and add your own shortcuts / launchers / .desktop entry files to them. This page will show you how to make global menus; ones available to all users.
Start by creating the menu itself. Right-click any empty space on the Desktop and choose Create New... Empty File. Save the file as your-menu.menu Then open the file with Leafpad. Right-click it and choose Leafpad. Copy and paste the following into it:
</Menu> <!-- End Your-Menu -->
Save and "X" out of the file. Right-click and Cut the menu. Go to Menu --> System Tools --> LXTerminal (or Ctrl+Alt+T) and type: gksu pcmanfm to open the file manager as root. Navigate to /etc/xdg/lubuntu/menus/applications-merged [you'll see our christian.menu already there] and paste.
The rest of the time will be spent in the /usr/share directory. Make a folder in /usr/share/ called your-menu and another inside that named your-folder.
Comment=Dektop Entry File
Save and "X" out of the shortcut. Now, add the icons for everything; the menu, the sub-menu and both shortcuts inside. Navigate to /usr/share/icons. Right-click and choose Create New... Folder and name it Your-Menu. Paste the following icons inside:
Save and "X" out of that shortcut. Right-click an empty space in that folder again and choose Create New... Empty File. This time save the file as your-folder.desktop, then right-click it and choose Leafpad. Finally, copy and paste this text into it:
Exec=pcmanfm -n /usr/share/your-menu/your-folder/
Save and "X" out of the shortcut. See what you've come up with. It should be there already, but if not; enter lxpanelctl restart in LXTerminal, or log out and log back in. If you still don't see the menu, restart.
The following menu was created for guests of a Family Promise affiliate to provide quick access to community resources (Family), churches they'll stay in (Hosts), places to look for employment (Work) and the Zoho mail email login page.
We began by creating a Family Promise menu icon (above) named Family-Promise-Menu.png that matched the default icons in the main menu, yet would still stand out. We saved this and many other icons / images in a folder inside /usr/share/icons called Family-Promise.
The following text made up the family-promise.menu we saved in /etc/xdg/lubuntu/menus/applications-merged:
</Menu> <!-- End Family-Promise -->
We created a family-promise folder in /usr/share, which in turn, contained the folders of family, hosts and work. Inside those folders, were the appropriate website shortcuts (we also added bookmarks in the Bookmarks Toolbar of Firefox that would take Family Promise guest to the same websites).
We created the family-promise.directory in /usr/share/desktop-directories with the following text:
The sub-menus opened windows (folders / directories) containing shortcuts to the website categories that corresponded to the sub-menu names.
Note: to avoid guest distraction and prevent abuse; Internet apps were removed, all bookmarks (other than the ones shown above) were deleted and these machines were whitelisted.
MORE INFO See Adding LXDE start menu sections (or “sub-menus”) and Adding LXDE start menu entries and desktop shortcuts on The skiing cube. Openbox Root Menus, Sub-Menus, Pipe Menus on Debian Linux Openbox Guide. Also see the GUI application MenuLibre on it's homepage and / or watch the video How to install MenuLibre on Ubuntu 16.04 on YouTube.