When I paint in oils, I load up several brushes with colors. I use the loaded brushes to apply the paint, switching to a fresh dry brush to blend and soften the edges.
Resin bark before and after paint
This bark is slush cast from a silicone mold I took of a log. I painted it in layers, starting by pushing dark blue into the cracks and details and wiping excess paint from the high points. I toned some areas with a more yellow-green, and finished by adding pink accents.