How to make posts of facebook timeline private?

[H]

You can also adjust the individual settings on each post by clicking the little icon on the top right hand of it. A drop down menu will appear that enables you to select different options like "public", "friends only", "only me", or "custom" (which controls which individuals you want to grant access to the post).

PP gave good advice on how to set up a default setting for every post.

Hope that helps.