I'm making this for my sister - a crochet hat with a flower above one ear. I tried to make a spheric shape but as I have no experience concerning this area I had to undo rows several times..
The technique's quite easy. Here you can see my moves when making a chain. You may start with a knot, you prickle the hook in the knot, pick the wool and pull back throuhg the eye. This is the first loop. Now you have it on the hook and the following ones you'll do just by picking the wool and pulling through.
I made about nine stitches and finished the circle with a slip stitch - prick the hook into the first loop that you made, cast the yarn and pull back through both loops.
The pattern consists of plain double crochet. Make about two chain stitches (a fake first double crochet) and then advance as in the picture. Cast the wool on, poke the needle into the circle, cast again and pull back. Cast, tuck through two loops, cast, tuck two and that's it. Finishing the row is made by a slip stitch again - you prickle into the upper part of the first (fake) double stitch.
In the following rows you don't jab in any circle, you may notice something like an embroidery chain stitch on the edge - prickle under one stitch (they look like little heart:-) ) or just under one thread of the two. I prefer the whole heart.
I hope my explanation's quite understandable. Wanna try it? Start right now! ;-)