Looking through some of my books, I'm seeing quite a few tisanes mentioned in context of Midsummer day. This is the day in general to harvest herbs for their greatest magical potency.
NOTE: Magical herbalism differs from medical herbalism; it acts on the spirit rather than the physical body. Seek professional medical treatment for medical needs, and enjoy magical herbs as a complement to traditional medicine.
Chamomile is sacred to the sun, and connects you with the inner powers of healing and regeneration. It encourages a good night's sleep. Avoid chamomile if you are allergic to ragweed.
Fennel ws one of the nine sacred herbs of the Anglo Saxons. Hung over the door on Midsummer Eve, it keeps away evil spirits. To make fennel tea, curs one tsp of fennel seeds and simmer in 1 cup of water for 10 minutes. Strain and sweeten with honey
Lavender is an all-purpose magical herb, promoting relaxation and peace. On Midsummer, go to a place where the faerie are known to congregate, inhale a sprig of lavender, and you may be treated to a visit from the faerie folk. Lavender tea is made by steeping 1 tsp of culinary grade lavender in 1 cup of boiling water for 10 minutes.
Happy Midsummer to everyone in the northern hemisphere, and happy Midwinter to everyone Down Under!