I drew the labyrinth in as a string and then allowed it to fade to the background as I filled in the spaces around it, picking new tangles each layer out from the center. My labyrinth was a bit off center, so follow the river path to it.
I'm still very new at this, so there's no shading, and I haven't quite worked out a line density that I like yet. But overall, I love the result of this.

Tangles used: Kuke, Flux, Tri-Po, Half Onion, 'Nzeppel, River, Tipple, Fescu, and Hepmee.