Visualise a tree [or leaf]. See the image and the light that lights it up. Repeat this for different trees [or leaves] for a few minutes.
Now direct your awareness to focus on the light and hold it without any images appearing.
Balikana is the moon-like glow that remains where the mental pictures used to be. If your mind wanders and starts to create images, quickly dismiss them and bring awareness back to balikana, the imageless light.
paraphrased from Innersearch Shum Tyeif Notes; my inserts in square brackets
Shum Tyeif Mamsani for the Month of January
Read more on Shum Mamsanis in 12 Shum Meditations