Oyster stitch is complex looking, but infact easy. It is a combination of a single rossette stitch loop and the lazy daisy. This stitch is where lazy daisy stitch encircles the rosette stitch loop, or in other words, the rosette stitch fills the lazy daisy. You get a slight embossed feel from this stitch and can be used for small petal or leaf , or any similar formations.

You need to know the rossette stitch and lazy daisy to be able to do oyster stitch.

oyster_stitch_1          oyster_stitch_2
Fig 1: We begin by doing a rossette stitch loop. So, we bring the needle out through A, put it in through B and bring it out through C as shown above. We loop the thread around the needle to form a twisted chain loop.   Fig 2: Once we get a twisted loop, we take the needle beneath the right leg of the loop as we would in rossette stitch.
oyster_stitch_3   oyster_stitch_4
Fig 3: Now, we will encircle the rossette stitch with the lazy daisy. For that, continue by putting in the needle through A (where the right leg of the rossette stitch begins) and bring it out from C. Loop the thread around like we would for a lazy daisy, as shown above.   Fig 4: Pull the needle out from C and anchor the lazy daisy loop.
oyster_stitch_5   Fig 5: A finished oyster stitch would look like this.