Here is a simple example of using FvwmButtons as a panel that contains 6 Icons to launch applications.
First determine the layout of the buttons. I am going to use 48x48 pixel icons with some padding so I decided on 6 60x60 pixel buttons positioned as shown
So this means the Buttons need to be 60*6 = 360 pixels wide and 60 pixels high. Next I want to position them in the middle of my screen 50 pixles from the bottom. To put this dock in the middle of my screen I calculate that half my screen is 1920/2 = 960 and half my Buggons width is 360/2 = 180. This puts them 960 - 180 = 780 pixles from the left end of the monintor.
Putting this altogether I get a Geometry string of the form
Next set the Colorset of the buttons and the Frame to 0 (so the buttons are just a solid background color). Then divide the Buttons into a grid with 1 Row and 6 Columns. This makes all the buttons the same size of 1x1. Then define the 6 Buttons. Each button is just an Icon and an Action that runs a program when clicked by the mouse.
Be sure to define the Colorset and add some Styles for the Buttons such as no Borders or Title, and WindowListSkip so it won’t be on window lists.
Then run the Buttons by using the following command, or optionally add this to the StartFuction so it loads when Fvwm starts.