Usually, Kali is not recommended unless she calls out to you.
She is a mother, but a ruthless one.
We need to prepare for awakening such fierce power. In Tantra, this is how we do it.
- Start with Ganesha - strengthen the root and sacral chakra so that she does not blow you up - energetically (causing delusion, health issues, sexual deviations) or materially (loss of wealth, loved ones, etc.)
- Balance her energies by doing practices for Bhairava who is grounding. She calms down only when she elicits the energy of Shiva as Bhairava
- Connect to Gurumandala - an entire lineage of enlightened masters who can etherically assist you. Gurupaduka mantra is this secret seal which gives lineage connection and is imparted during Shaktipata (transmission of power)
Kalika Ashtakam is perfect and captures her in two aspects - as the deity with a specific form, and also her truth as the Divine Consciousness that transcends names and forms.
I usually always give Durga mantras when folks come to me (dum durgaayai namaH) and never Kali.
There was a lady who came to me in Seattle and asked me for Kali’s mantra saying she wanted to chant it. I refused for the above reasons. That night, when I was asleep, the Mother shook me, physically and it felt like a hundred thunderbolts hit me (mind you, she is not hurting you, it’s just her tremendous energy) and said, “Give what she wants, she was my devotee for last several births, let her continue on my path”. So, sometimes affinity comes from practice from previous births/alternate timelines. When she chooses someone Herself, then rules are no longer applicable.
Of course, praying to her is okay for anyone, but mantras need caution. It is like invoking angels for blessings through prayers and faith vs ritualistic evocation or summoning of the mighty archangels.