This is what I made! Here is another example, below, which is slightly neater. It's all in how large or small you draw your heart.
(Yes, that is a mini Tardis. No, I don't watch Dr. Who. =) It's for a friend!)
For the purpose of this tutorial, I will assume you already understand how to do the Coptic stitch. Pinterest has a lot of great tutorials!
Start off with a stack of prepared signatures, folded and trimmed to the size of your cover. Clamp them together firmly with binder clips. You might be able to see (faintly) that I made pencil marks where the two rows of stitching will be at either end. If not, look at the above pictures to get an idea where the end stitching should be.
Trace a heart in the center. The bottom signature has two dots - the point of the heart is made by attaching the cover. The top center point of the heart is made on the 3rd signature down. After marking everything, punch all the holes.
You will be sewing the heart from the top down. Punch two holes in the cover to match the two holes in the top signature.
Start on the left side - pull the needle and cord from the inside to the outside through the first hole. You will begin by attaching the first signature the cover.
I attach the cover by wrapping the cord twice around the cover hole. (This is on the 2nd hole.) The cord goes out:
Then thread it in through the hole and bring it up between the cover and the signature.
Pull it tight and thread it in through the hole and up through the crack again:
Now slip the needle behind the two strands and pull it through snugly. Wrap it around one more time to secure.
(That is my method of attaching all the covers on my journals. Again, for more details, there are a lot of great tutorials out there! Maybe someday I'll write one. ;) )
Skipping ahead to the second signature, this is how you make the top bumps on the heart. You can see that there are more holes on the second signature than on the first. Basic rule: every stitch must loop around a stitch below. You will be working from right to left on this signature. Out through the hole...
Loop around the stitch below and insert back into the same hole.
Bring your needle out through the 2nd hole and loop around the same stitch as the last.
When you finish both bumps, it will look something like this:
Continue on with the 3rd signature (left to right now).
Now you are to the top pointy part on the heart, and there isn't a lower stitch to loop around! What is there to do?
Easy - just loop around the cord in the inside of the signature.
Come out again through the center hole and loop around the next stitch on the signature below.
Continue on. It's pretty straightforward from here. The sides of the heart will slant - just make sure you don't pull the signatures out of alignment.
Now to attach the top cover. When you reach the middle, loop around the cover ONE time, then wrap the cord around your loop, as shown.
Insert the needle back in the same hole.
Bring your needle out through the other side of the heart. Loop through the cover hole once. Insert your needle under both loops and wrap the cord around two times. Insert needle back through the hole from which it came.
Finish attaching your cover. This should be your end result:
It's a little crooked, but be careful to trace your heart exactly how you want it and pull your stitches snug.