Fresh is best, however you can used dried, crushed leaves. Alcohol that is at least 80 proof.

Clean jar.

Slice the nettle into thin strips, then bruise them. Add to the jar or crush your dried leaves into small pieces. Fill the jar and cover with the alcohol. Put lid on. Infuse for 4-6 weeks shaking every day. When done pour through a sieve to strain out all plant material. Store in a cool dark place for up to 5 years if sealed.

Take 1/2 - 1 tsp daily.