3D-flowers need more stability. You do not reverse the work while working in dense double knots.
Work a row of seven base loops into the fabric as before.
Instead of reversing the work at the end of the row you put the needle through the first worked loop from behind. You
pull the needle through and carefully adjust the thread to the length of the row just worked.
Fix the thread to the base loop with a double knot.
For working the next double knot in the next loop you slide the needle under the next loop, but under the spanned thread
as well. You have to catch this spanned thread with every further double knot.
At the end of this triangle you return to the fabric, just as with all the other triangles.
These spanned threads produce the typical structure of the 3D-flowers.
Most Flowers are worked from these dense double knots, exceptions are rare.