I used a runes for my own first black magic working.
As with all magic, timing is key. Make sure the moon is favorable for the working. The JOS astrology PDF has decent info on this.
Second of all, when choosing your runes, make sure you figure out what you want the working to accomplish. It might be a lot easier to do certain things to certain people depending on their situation.
Thirdly, make sure you are spiritually stronger than the person you are cursing, otherwise the working will backfire or yield no results.
For the working itself -
A 40 day working is best. Start during a full waxing moon when the sign is favorable for black magic.
Do a standard ritual, ask the gods for help with the working both in protecting you from the influence and inflicting damage on the offender. Do a THROUGHOUT cleaning before and after. If you are unable to feel or see negative energies in your aura do not attempt black magic. Having these linger can be extremely dangerous and you could end up cursing yourself instead. I used SURYA and visualizing the sun above my head. Do the runic working. Make sure you externalize the energy as you vibrate, never come in contact with these. I imagined a glass bead that was getting filled up with black energy, one for each rune. After you finish vibrating the runes, add the filth from the pile where you cleaned your aura into the energies of the working and start affirming your desired outcome 9 times. You can use AUM after each repetition or just on the end of the affirmations themselves, up to you and how you feel about it. After you are done, ask your guardian to send the offender the energy or do it yourself, or do a bit of both. Then do another THROUGHOUT cleaning. After the ritual is done, don't think about the person or if the working is doings its job etc. Just pretend they dont exist and that you didn't do anything. Thinking about them randomly while you're doing the 40 day working can interfere with the results.
Good luck!