Which session / frequency to contact the spirit world

This probably hasnt been asked and there might not be many experiences in that regard. Im just wondering, which frequency could aid in my meditation, to get in contact with the spirit world.
Background: my wife died 10 months ago (after 23 years together) and while im contact with her, i try to deepen our connection.

She told me right in the beginning in one of my meditations, that i need to raise my vibration to come in contact with her.
I found, being in nature does strengthen our connection a lot. Meditation itself didnt so far, but that might be because i have a hard time going deeper - probably because of still being in a grief zone. Same goes for OOB, i dont even get into the hypnagogic state.

I hope the Kasina will at least help me to relax but maybe also help in a way to dissociate a bit from my body or help raise my vibration... im still unsure what that even means.

Thanks for any input!

I don't think any particular session will be of benefit to you. I think you need to find a session (in general) that works for you, and once you're "in the zone," then you can start delving into those memories and feelings that are associated with the person you are reaching out to. That's what happened with my dad. A week prior to his passing, during a Kasina session, I relived (?) a dream memory / nightmare about his battle with cancer. The emotions started floooding and I was crying during the session, and out of nowhere he came forward (he was still physically alive, but he was drugged and sleeping most of the day) in the form of a blue light / consciousness and he relayed the message that I need to be there for mom and "help your mother out," via finances and maintaining of the house, etc... Not the message I wanted to hear, but it's what he had for me. I've not tried to reach out to him since, but I am sure with some INTENT and trial/error, it is achievable.

Thanks for replying and sharing your experience!

Well, its not needed anyway as im constantly in contact with her. And to be honest, every attempt from my side ends in nothing... i understood, that my task is to heal and that means facing burried emotions.
She is here constantly anway and any deeper connection then that will come, when the time is right (im healed enough).

This leads me to my next question, which i will create a new post for.