Hi Brian,

>>NOW, you must explain how you did it! Please!

Very simply for that model

Create a sphere. Then in one of the 2d views draw the curves for the pattern of the veins:



Project those curve to the sphere surface. (you could of course of drawn those directly to surface if wanted in V2)



Sweep circles (or whatever shape you think best) on the surface curves with the "pointy end" option.



Once done, you can then trim the sphere in half, and boolean the main vein.



Using a control point curve, start at one of the intersections then draw using "on surface" snap the shape of the outside of the leaf, then finish the curve at the other intersection (as next pic)



Using the drawn curve, trim the sphere.



Hope I have explained OK.


- Steve