Cut a hole in a piece of paper.
Draw what might be climbing out of the hole, surrounding the hole, dripping from the hole etc.
I visited the Macduff Marine Aquarium and was fascinated by the octopus. This inspired me to doodle some tentacles dangling through the hole.
The second time I cut a small hole. It made me think of the pupil in an eye. I am going to use this doodle as a viewing frame when I go out looking for pattern and detail. It will help me to focus on detail and switch off from the surrounding environment as I draw.