There is a lot of similarity between this lesson and many others in Woodcarving Workshops: repeating cuts, letting the gouge do the work, estimating by eye etc. I'm tempted to give you links but I'll just say, bear this thought in mind everywhere you look on this site!
When you do the final cut to the outline of the secondary leaves, stab through the paper beneath. You'll find the split carvings come away from the backing board more cleanly.