I have changed Desktop on Lubuntu 18.04 LTS because default settings Lubuntu 18.04 LTS is understandable manipulation for beginner Linux® desktop users; however, it is a little bit uncomfortable manipulation for mature beginner Linux desktop users. Therefore, changing panel settings is the best way of favorable manipulation for mature Linux desktop users in Lubuntu 18.04 LTS.
Here is about screenshot of panel setting on Lubuntu 18.04 LTS. Move mouse pointer to panel -> The panel position is tool items on Desktop -> Right click on the panel blank area -> Opened the dialog setting menu -> Then, choose the panel setting That's it. It is able to open panel setting menu.
I changed position of the panel in Lubuntu desktop because first priority panel need comfortable manipulation and necessity of visibility. It is only in my opinion. Of course, it's up to you changed comfortable panel positon.
I changed tab menu, and Panel Applets menu has already set default apps. Panel Applets are able to be changed by these right side buttons. I changed expanding of the window. I have deleted default applets except menu applet on the Panel Applets menu.
Caution: Sometimes error message displayed on desktop. Please do not worry about it. It can only choose to want send to error report message or does not want send to error report message. I will write about this issue to last screenshot on this article. Please do not miss it.
I have added second panel on Desktop below position. Alignment and Size settings ware same as first priority panel settings.
Appearance setting is same as first priority panel setting, too. Thus, I have finished plain panels on desktop in Lubuntu 18.04 LTS.
Finally, this screenshot means Error report message window on Lubuntu 18.04 LTS. I said that changed panel setting sometimes displayed error message on Desktop in Lubuntu 18.04 LTS. Here is it. When you want send error report message, you need password, or you do not need password. It depends on your choice.