The center of a rose is made of 2 bullions stitches with 2 threads and 2 wraps, starting and finishing in the same hole 

The rose is made of a succession of bullion stitches worked around and overlapping slightly.

What I call “the first round” in the construction of a rose is articulated around the center. It consists of three petals that form a circle.

Here is the first. It is a bullion stitch of about 12 wraps. It starts half way of a center stitch, turns around their tip and ends on the other side also to half way.

This is the second petal. The bullion stitch of about 15 wraps starts at the first half backwards relative to the direction of rotation you have chosen. It ends at the opposite.

To embroider the third petal, as before, you have to step back up to half of the preceding stitch to start the next one. You can put 17 or 18 wraps and the stitch has to end where the first petal is starting. 

This completes the circle formed by the 3 petals.

When the first round is complete, just embroider the outer petals to complete the flower.

For this, you have to work as before, but more freely. Always keep turning in the same direction and also step back to start the next stitch. This is what allows petals overlap. The bullion stitches from this level does not exceed 14 wraps.

When you get the desired effect, that’s it, the rose is finished.