If you would like to create a custom signature for each post, then head over to A Little Unhinged who has done a useful post on how you go about it. This is the link. Thanks for the permission to refer to this, Gwen.
I haven't done this myself yet - I'm not sure yet if I want to. As you know, I am a bit minimalist about my blog design. It is all about the content, after all, isn't it??
PS Another little tip - did you notice that the Pin it button is underneath the first image? If you don't put the image first you will find that your post shows up in your followers' dashboards with only the Pin it button as the image - which isn't very attractive.