Here is the template I used to cut the trefoil pattern. I purchased a plunge router and this is the first project I used it on.
The pattern repeats at a 60 degree rotation. The two 0.25” holes are used to align the template on a 60 degree axis.
I tried a couple of tests first. The top was too deep and too wide. The lower test is narrower and only 0.125” deep. It looks better.
Here is the final assembly.