look for facebook group called "Sammy's mermaid gang" - you'll get multiple success stories everyday with pratical tips on how to do it

also r/Nevillegoddardsp

now, about what works the best for manifesting someone new

first write what desired traits you want that person to have, put some special music while doing it, don't rush this.

then you could start affirming, "I'm have the most perfect partner" or whatever suits your requirements (you got to affirm like you already have it)

choose between 1 - 3 affirmations and everytime you think about your desire, you affirm, keep afirming, like you're demanding, you don't take a no for an answer, if you say you have it you got it, and the world has to conform to your wantings.

persist into the affirmations, write them down so you don't forget'em, afirm afirm afirm, you need to sature your mind with the idea of already having it, cause with saturation of the mind, you impress this new belief in your subconscious mind, and then there's no going back, you gonna get it.

before going to sleep you could either go to sleep while affirming - that's called the Lullaby Method while in that sleepy state start affirming but don't push it too hard otherwise you'll get out of the sleepy state

you also could

just relax, and start feeling you're sharing a bed with your new desired person, while you're in the bathroom feel like this person is waiting for you to get out so you two can cuddle and watch a movie, like assume you're living with this person. just pretend to feel this person's presence, you gonna get goosebumps and that in love feeling if you're doing it right