May this holiday season bring you everything you've been wishing for. May you find yourself surrounded by loved ones, enjoying the warmth of their company. And may you find happiness, joy and peace in your celebrations.
I'm not actually a lefty. I just had to hold the camera with my right hand to take the picture. :)
As you practice and get more skilled with the technique, try to apply more pressure at the beginning of the brush stroke and decrease the pressure toward the end of the stroke. This will make the branch thicker at the start and thinner at the tip.
You can also use different sized rigger brushes to create different line widths. I used a size 6, a size 4 and another smaller brush for this practice (see picture).