Secret #1 got us the biggest profile picture that Facebook will allow. But the thumbnail that Facebook creates from my profile picture didn’t look that great. I had my logo and a call to action. But the thumbnail showed me a little of each. That is not what I was after.
So secret #2 is how to control your thumbnail.
I still have a 200 pixel (px) x 600 pixel profile image. But I redesigned the image to create a sub area that is 176px x 176px. I shrunk the logo to fit within this box. I made this box yellow, so my explanation would be clear. This box can be anywhere within the 200px x 600px image.
I updated the profile photo, with the same steps I used in secret #1. But now there is one more step. Just beneath my new profile graphic on the Change Profile Picture page, is a link to Edit Thumbnail. I clicked that, and following the instructions, I dragged the image to adjust. Click Save, and you are done. Note that the thumbnail didn’t look right on the fan page until I reloaded my page in the browser. The change was there once everything reloaded.