There is something quite magical and romantic about a dip pen with a beautifully marbled handle and a gorgeous nib. The feel you have as you dip the pen and make a mark on the paper with the liquid ink cannot be matched by a felt tip pen.
For this ginkgo leaf I have chosen a sepia ink called Peat Brown by Winsor & Newton. It is not completely waterproof so it will bleed a little when I add the watercolour wash, but it will resist enough to keep a sharp line. 
After transferring the outline of drawing and a few main veins to a smooth watercolour paper using Tracedown transfer paper, I start the outline using a medium nib. I am using a mapping pen with a flexible nib so that I can change the line width by pressing harder or relieving the pressure.
I then swap the pen to a finer nib for the veins, this time using a Manga pen by Kuretake. Like I did with the drawing, I start with the central vein, then split each half, then split each quarter, filling in the shrinking segments with more veins, always making sure that the veins never cross each other. The build up happening naturally at the top of the stem gives depth inside the fold.
After all the veins are drawn, I add a little bit of cross-hatching to the side of the stem and of course the blemishes that will show the life of the leaf before it ended up on my painting table.
I will wait overnight for the ink to dry thoroughly, then erase the pencil. The drawing is now ready for the third and last stage, the watercolour wash.
Here is a link to the video showing the inking of the leaf: https://youtu.be/ZdtFmAzdONg
Happy inking!
Some materials used in this tutorial are clickable as affiliate links to the suppliers.
Sandrine Maugy 