There's an awful lot of requests for watercolour versions of portraits in the portraits thread, and I figured that it wouldn't hurt to at least throw an alternative to asking other people out there, whether anyone uses it or not.
For this process, you need:
The GIMP (https://www.gimp.org) I'm using version 2.8.14, so some things might look different, but hopefully not.
A non-circular brush for the GIMP. I think the Acrylic 1 brush that I use comes standard, but I could be wrong
A little