Amazon executes small JS code to set and delete cookie before login, here is part of source code:
var exdate=new Date();
document.cookie=c_name+ "=" +escape(value)+
((expiredays==null) ? "" : ";expires="+exdate.toGMTString());
document.getElementById(nodeId).style.display = 'block';
phantom.cookiesEnabled = true;
var webPage = require('webpage');
var page = webPage.create();
page.settings.userAgent = 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/44.0.2403.157 Safari/537.36';
Now, just submit form using your username and password, and you can login.
Here is really good resource of How to login Amazon using PhantomJS. The same pattern can be used to login any other website.
phantom.cookiesEnabled = true
cookiesEnabled = true;
That sounds like a whole lot of relevant information to include in your post instead of just vague instructions for how to set default settings.