For best engraving we want to hold the side of the shot glass level. We want something that can consistently hold it level and can work with multiple brands of glasses that may vary slightly in sizes.
Take some measurements for the general idea. The base is 10mm smaller than the top. To hold this tipped we'll want something around 14mm as a baseline lift.
The base of the shot glass is 33mm so we'll create an opening at 35. This will allow it to fit slightly past the base and also keep it flexible if we have different brands that differ slightly.
The final upright part will need a square with a half circle cutout to hold the shot glass and a couple of tabs so it can slot into a base. Let's start with all of the shapes we need to make that happen.
Create a square that is 14mm tall and 40mm wide.
Create a circle that is 35mm in diameter. Place the circle so that the bottom of it almost touches the rectangle's top.
Create two squares that are 7mm wide and a little under 3mm tall (assuming you are using 3mm basswood). Place them at the bottom of the rectangle.
Group the two little squares together. Select all shapes and then center them horizontally.
Now we need to take those separate pieces and turn them into the final upright.
Select the larger rectangle, unlock it, and then extend the top of it up to partially overlap the circle without changing the width.
Select the little squares and the larger rectangle and combine.
Send this object to the back.
Select the new combined object and the circle and Subtract.
We're also going to need a base for that upright to slot into.
Create a rectangle 30 x 70mm.
Place rectangles that match the two little ones we created earlier but the height should be thinner to match the thickness of the wood. I recommend using a gauge here to measure the thickness.
Subtract the little rectangles from the larger one.
Cut out the two pieces from 3mm basswood and glue them together. I used the default basswood settings (100 power 35 speed).
Let's test it out! Set a shot glass on the jig, place the level on top of it, and push the shot glass back until it's level. Use a piece of tape to hold the shot glass at that location. You're ready to go!