Meditation is important when it comes to every aspect of this writing process. From before conception and getting it out on paper, to the stage of completion. Starting any work of art with meditation helps with making a smoother transition. It's kinda like the oil. Creates less friction during the creative process.
Getting a good session of meditation is great for before writing but it also helps especially when you're at a tough spot in your writing process, to meditate afterwards. Quintin Terentino in an interview said he always gets in the hot tub after he writes. So I jumped on that train and decided that when my writing gets tough I'll push through then give myself a hot bath with candles, salts, and all. It really helps me transition and accept where I am in my process. Sometimes I let more ideas come at that time but I don't write them down then because this is a place of calm and I trust that if those ideas are important they'll return. But sometimes I can't help but jump out and write down them down.
Meditation in a valuable tool to have when you write and what's great is that there are so many ways to do it. Sitting quietly, walking, journaling, sipping tea, the ways to meditate are endless. Once you find which one works for you, it will really help oil your gears and get those words flowing.