It generally helps me to put myself in a situation where all I can do is feel. I think that if I can feel the emotions I want to write about then I'm more likely to be able to get words on the paper. My ways of doing this are usually to watch a drama or read a book or specific comfort movies/books that I know will bring out those feelings.
I also do a lot of "start writing about a scenario and just SEE WHERE IT GOES". A lot of the time, when it comes to writing, I think "if I write this down I have to do it once and get it right" but that's just not the truth when I can delete things, go back, and completely move sections of text easily. A lot of my stories have 30+ pages of me picking a nonsense plot point and running with it