Consent must be informed in all cases. If a user does not know the privacy policy of your website while using it, it is not informed consent. How do you make sure that the user is aware of the privacy policy while using the website?
Are you talking about cookie tracking? Most websites show their privacy policy or provide a link when you sign up, before one provides any personal information. Either way, nearly all websites have a privacy policy in their footer which can be read before continuing.