okay, I used to be really picky about how people would write about relationships, but now that I have been through the whole experience, I feel that now I can give better advice.
the relationship in general:
1. characters can fall fast, but make it so they're afraid to admit that. this creates a lot of suspense and tension on the relationship you're writing about.
2. slow is better (more suspense) but fast is okay too. just make sure that it's genuine if it's fast (by this I don't mean constant sex. that's not a real relationship that someone wants to really read about). moving slower also gives readers more time to fall in love with the relationship, which will make them more upset if a breakup ever occurs.
breaking up:
1. have the character be perfectly fine for the week after it happens, then have them break down about it. have them then be upset about it off and on (this is how my breakup went for me. don't be afraid to make it painful because it's not always easy)
2. don't be afraid to go deep with their sadness. breakups aren't always easy peasy and your character might be sad as shit. don't be afraid to express that
3. don't have them move on completely right away. they can try and move on but it might not work out for them because they're still not over the other person. don't feel pressured to keep your story moving romantically.
WILL UPDATE AS MORE IDEAS COME TO MIND
YOU ARE READING
scream fan fiction tips
RandomJust a girl who strives for a Scream Fan Fiction that isn't like the rest :) #88 in TIPS 6/25/18