I take Do Not Disturb by Apothekary (mix it with some hot water, let it steep for about 5 minutes before drinking). While it's not a silver bullet, I've found that it consistently helps with feeling chilled out before bed and if I happen to wake up in the middle of the night.
I think this and combining mindfulness have really helped me (I highly recommend this book, it made me rethink what insomnia is and gives some good tips) https://www.amazon.com/gp/product/B00L9C2IBM/ref=ppx_yo_dt_b_d_asin_title_o02?ie=UTF8&psc=1)