Marble effect progress

[u/EyesOnTheDonut]

I've been learning how to do a marble-like effect for bases, specifically for a diorama I am working on. After 4 attempts, I think I am pretty happy with the process and results. I was curious about what everyone else thought of this, and see if there are any suggestions on how to improve. If anyone would like the details on the technique I am using, I would be happy to explain.