Break-ups are hard. And by hard, I mean they're the actual worst. Your stomach drops, and your heart skips a beat in an entirely unromantic way, and you can't always figure out what went wrong. We've all been there. Even if we're the one doing the dumping, it's hard to tell somebody that you're just not feeling it anymore.
Sometimes our friends go through break-ups. Sometimes our friend's break-up is harder than our own break-up because the right thing to say just doesn't exist. So we tell our friends that it'll be okay, that we're there for them, that they deserve better anyway. Then we hope that our words are actually helpful and soothing, even though we know the whole time that nothing we say can change how much our friend is hurting. We know this because we've been through our own break-ups and heard more advice than we really wanted to.
Tell your friend what you would want to hear. Tell them it will be okay and that life gets better. Because it's human instinct to tell people that. Then tell them you understand that it's not okay right now, and that they can take a little bit of time to be less than okay.
Ask them if they want ice cream, or french fries, or a salad (because healthy food makes your body happy). Just be sure to eat with them so they don't feel too unhealthy when they order a large fry and a large shake at the same time.
Listen when they talk about their ex endlessly. They might spend three days blabbering about how great the relationship was, or they might wait a week before they're ready to talk. That's okay. They just want somebody to listen.
Tell your friend that there are other fish in the sea. Then apologize, because they probably just want one specific fish right now.
Support the choices your friend is making. If they want to drink, make sure they're safe. If they don't want to drink, don't push. Maybe your friend wants a new haircut, and say it looks great. Whatever you do, don't criticize. (Unless of course your friend isn't being safe. In which case you should very carefully express your concern.)
Break-ups are hard. Watching a friend go through a break-up is hard. None of us have super powers to make break-ups easier for our friends. What we do have is ears to listen, shoulders to cry on, and hands to hold.