First I look up the Unihan number and then use that in Inkscape to create a black character I can edit.
You use Control U and enter the unihan to generate the character.
Shuang Frost
Now you can change the color or size or add filters in Inkscape or export it as png into Gimp and use other filters. I've elongated this to suggest seal script styles and applied a filter that I think will enhance the final edit in Gimp.
Finally I use Gimp plug ins and filters to create this effect
I'm very partial to using the Textured filter but there are many others you can experiment with.