Question

any tips on how to harmonize with someone

Answer 1

first off pick the octave you want to sing for example alto or soprano, even tenor and bass then have the other person, meaning the person in which you are trying to harmonize with pick the opposite octave that you chose

Answer 2

You have to build a sort of connection first

Answer 3

And then you work on the music part

Answer 4

you gotta moreso use tones that compliment each other, for instance, most people use a high tone and a low tone but itd probably be better if you had a mix of tones like someone high someone low and someone like in the middle, but honestly depends on what youre going for, just watch a youtube video or something