Find a good time and place to have a calm, sit down talk about your boundaries in regards to a friendship. Probably too simplistic a response, but: Of course, that's no guarantee that this girl will ever come around. You may find you and your ex argue when you get together. If you shared belongings or lived together, wait until your lives are completely separate before pursuing a friendship. When someone was important to you romantically, it's natural to want to hold on to that connection. If you find yourself feeling you have more to say, or still need closure, it's not the right time to be friends.
Let your ex know directly what kind of contact is still appropriate and let them share their feelings as well.
If you need to talk about a few more things before you can be friends, have a discussion with your ex about any loose ends a few weeks after you break up. Already answered Not a question Bad question Other. Fundamentally different world views or different lifestyles can cause a breakup. Some people may be ready for friendship in a few weeks, while others may need a few months. Be sure to tie up practical loose ends.