I wanted to adjust the angel of my Show 2 to be a little more upright than the angle it normally sits at. I tried to make it sit primarily on the rubber pad on the bottom of the device, otherwise the bass from loud music shakes it too much against the stand. That means it won't sit flush on the very bottom front or top back (the gap you see in the rear view picture), that is OK and actually better for sound. If you play loud music and this sits on a hard surface you may need to add rubber to the bottom of the stand so it doesn't walk around. Pictured in green so you can see the stand vs the Show itself, but printing it in black or the color of your counter/device would make it blend in pretty well.
This is for the Echo Show 2, the bigger second gen model released late 2018.
Inspiration from this: https://www.thingiverse.com/thing:2720386
IGES source file included in case you want to make any adjustments.
I printed with Cura's new Gyroid infill just to try it. The device is pretty heavy and bass from music can shake it around a little so don't be scared to make it sturdy.