Skullcap is my personal favorite. Lemon balm, chamomile, and hops go nicely with it also, or individually/instead of. My own personal blend that I’ve labelled “nerve tonic” is comprised of lemon balm, chamomile, hops, and skullcap. It makes a lovely cup of bedtime tea.
Another one I like is just to infuse either a few leaves of lemon balm or a spring of lavender in my bottle of ice water to sip throughout the day. It helps to steady the nerves and induce a feeling of serenity without undue drowsiness.