Abstract in Grey/Orange
Based on https://youtu.be/Z9zPp_-GkMw
Take medium-sized watercolour paper (Arches). Dampen it.
Take a damp brush and cover paper with a good coat of white gesso.
While the gesso is wet, brush on a narrow, soft border in panes grey around the whole paper. Fade to a white.
Allow to completely dry.
With a black permanent marker draw an abstract design over the whole canvas with 1-2 cm spacing between elements. Draw circles, parallel lines, squares, rectangles, ovals, squiggles, waves, triangles, forks, crosses, t-shapes, ladders, gates, fences, roads, arcs, dots, leaves, eyes, spokes, branches, contours, whatever.
Use titanium white to bring out some edge shapes.
Fill about 30% of areas at random with paynes grey, diluted with airbrush medium.
Lift some grey paint while still wet with tissues to get gradients.
Mix yellow ochre, cadmium yellow, and a touch of burnt sienna and cadmium red. Dilute with airbrush medium.
Fill 30% of areas. Lift some paint while wet with tissue/brush to get soft transitions.
Darken a few of the already darker orange areas with burnt sienna and cadmium red. Soften transitions.
Glaze darker grey areas to deepen with panes grey using tissue to soften transitions.
Use Cerulean blue glaze over some 5-10% grey areas.
Highlight 0.5% of smaller areas with gold.