I really like this stitch, fishbone stitch. Especially when using variegated threads, I love seeing those patterns emerge. It’s most often used for leaves, but just look at my little sample there, they look more like feathers. And I think it can be used for lots of different shapes too. Like hearts, for example.
It’s a pretty easy stitch, but it takes a bit of practice to get the sides nice and even – I’m still working on that! ;-)
In this example I’m doing a leaf shape, so I started by drawing that on my fabric. This is mainly as a helpful guide, don’t get too hung up about it* if your leaf doesn’t end up following the shape exactly.
Make a small straight stitch (approximately 4mm) at the tip of the centre line, bringing the needle up at A and inserting it at B.
*The perfectionists among you are of course completely welcome to get hung up about it, and unpick things to make them just so. ;-)
Notice that the needle is always inserted along the centre line.
Step four is basically a repeat of step two and I think you can probably guess that step five would be a repeat of step three. :-)
To fill the shape you alternate between making a stitch on the right and left side of the centre line, moving down the sides until you have filled the whole shape.
When you are done, you should have a shape that looks similar to the ones in the top picture. :-)