If you're not sure you want to delete your Facebook account completely, but think maybe you might want to reduce your use of it, then uninstalling the app from your phone is very helpful (Assuming you have it on your phone).

That worked very well for me. I used to have it on my phone and would check it all the time. Then I decided I didn't want to do that so I uninstalled it from my phone. Doing so helped me reduce and eventually stop using the website.

In between those times I also had a browser plugin to hide the news feed. So if I do login, I see nothing.

Now I'm basically rarely on Facebook. I have an account, but I don't feel I need to delete it because the account doesn't control or affect me. I can still get messages, and Facebook keeps trying to get me back into it with their notification emails, but I'm in control and I feel great about that.