You can now keep all you new posts under wraps and with the appropriate visibility, but what about your old posts? Or if you change your mind about should see something?

Timeline Edits:

From your Timeline you can change the visibility of any post. As always we have two icons to look for next to the post – either the “Friends” logo or the “Cog” logo (meaning other).

Hovering over either of these will tell you the visibility of that post.

To change the privacy simply click on the icon.

You’ll see the values don’t exactly match, that’s because Restricted Friends only get to see Public posts. To edit the visibility further you can select a List or two.
To really get into the Privacy of the post though, use the Custom Privacy option.

There are some useful options here, split into two sections:

• Make this visible to
• Hide this from

When hiding something from Lists or Friends you must specify them directly. When making something visible to Lists or Friends you have more options.

Friends of Friends is a good way of increasing visibility of something, especially if your friends have Friends that you simply haven’t added yet.
Friends is obviously everyone you’ve friended on Facebook, except those on the Restricted list and of course those you elect to Hide this post from.
Specific People or Lists works in the same way as the Hide option, but the opposite action.
Me: You can even have a Timeline littered with stuff only you can see. Suppose if you were careful, you could use it as a diary. Risky business that though.
So we save those changes and check the post again (hover over the Cog).

So I have successfully both extended (Friends of Friends) and restricted (Acquaintances) the visibility of this post at the same time.
Strange world.