Assuming Firefox…the best strategy I can find is this:

1. Set all cookies to be allowed, but discarded at end of session.
Tools | Options | Privacy | Accept cookies from sites | Keep until: I close Firefox.

2. Discard ALL your cookies.
Tools | Options | Privacy | Show Cookies | Remove All Cookies

3. Add exceptions sparingly for sites you need as you find them. Mostly this is just things like sites remembering you’re logged in. You can manage with no exceptions, but a few for your regular sites make life easier.

Navigate to the Login page for a site you want to make an exception.
Tools | Page Info | Permissions | Set Cookies: Allow.

I strongly recommend doing this for all “power” users. It cuts down a lot of the ability of advertisers to track where you go with virtually no impact on overall usability.