The only way writing can be considered meditation is when you use it to give you answers from your subconscious or to communicate with gods, kinda like a pendulum. You just put the pencil on paper and ask your hand to write the answer for you (while in trance / or not) for me I wasn't doing it in trance, but emptying your mind is a must. Last time I did it was a couple of years ago when I asked my incubus his name. Haven't used it since then.
Other than that, considering writing a meditation isn't a solution if it is just to empty your mind. This should be done with void meditation, which takes practice. Or use a rune for example, like the one Blitzkreig gave you as an example. Sol rune also pushes you to act, incites action, and it may not be necessary to do anything else, the rune will just make you meditate without thinking much if you use the right affirmation, as it has done for me.