There are many ways to get the effect of watercolour with digital painting software. You can get a good watercolour canvas texture image to use as an overlay and or underlay in Photoshop, Krita and other similar softwares or you can use software designed to emulate watercolour such as Rebelle, Expresii or Corel Painter. Of course you can also use traditional media and scan it in and do whatever you want that way as well.
I’ve been making a few videos and putting them on Youtube, I’ll keep making them as I experiment with different techniques.
Rebelle and ArtRage
Rebelle and Corel Painter