Add the dried calendula flowers and optional dried comfrey leaves to a jar.
Pour olive oil (or oil of choice) over the herbs to fully cover the herbs (it's OK if the jar isn't completely full).
Cap the jar, and make sure it is sealed tight. Label and date the jar.
Shake the jar once daily for 4-6 weeks to ensure the herbs stay covered and mold cannot form.
After 4-6 weeks, the oil will be infused with the calendula and optional comfrey.
Open the jar and strain out the herbs using a cheesecloth or fine mesh sieve. Store oil in a new clean jar.
Label and date the jar, then store your infused calendula oil in an airtight container in a cool, dark place until ready to use.