I am looking at building the login/registration part of a website (ASP.NET) and would like to see some example code or instructions on how to do this properly. For example, how to correctly use cookies and how to encrypt what is stored in the cookie to ensure the session persists until they logout/timeout.

I do not want to use the builtin ASP.NET Membership/Provider stuff as it looks painful to use and not very flexible. Please do not answer with 'This is how easy the ASP.NET Membership/Providre stuff is to use, just check this out and you will use it!' as I don't want to use it!