Invoking Hel

On a flat surface, lay the black cloth out and spread it neatly. Neatly lay the bones in some orderly fashion around the edges of the cloth. Place the black candle on the left side of the cloth and the white candle on the other side. Light both of these, and spend a moment relaxing, becoming calm, and clearing your mind. You might want to play some music, drum beats, etc. to help get you in the "mood" for the working.

Place the bread and the wine(optional) in the middle of these candles. Meditate, focusing on calling to Hel specifically. Say "Queen of darkness, Loki's daughter, hear and witness my offering" as you gesture towards the bread/wine. "Hel, hear me now, I call for your assistance". Wait until you feel as though the offering has been accepted, then move on.

Hel can be called upon for a variety of reasons. If you are spirit-journeying you would want to call upon her before traveling to her realm. But she also can be called to help offer aid to those dead or dying, alleviate who are sickly, etc. She can also be useful as shamans tend to call on her for information about those who have died, or to gain her approval so that they may commune with the dead. On the flip side, if you have issues with someone you may call upon her to resolve them, bring ill to the other person through harm or death, etc. Whatever your specific purpose is, state it now.

When you are done, you may say a short prayer or thanks to Hel. Hel
Patricia Monaghan did a good job of writing an example prayer:
"I hear you invoked every day by those ignorant of your power:Mighty Hel,Oh Hel.
Thus does she endure,the forgotten goddess, never far from us,never quite erased,
Oh Hel,dark mother,we always come back to you, always. Always."
After this is said or done, let the candles burn till they go out on their own.
You'll want to make a small hole in the ground outside and pour the wine in it.
Leave the bread somewhere where animals will be able to eat it.