Open a new document with size at will and color at will (I used white)
View attachment 98898
add a PNG image (no background) at will or cut out an image at will and make it an uniform color
View attachment 98899
Add an abstract watercolor background layer
View attachment 98900
Select the horse (ctrl+thumbnail to see the 'marching ants and clip the watercolor background to the horse layer
View attachment 98901
To work easily untick (eyeball) the horse layer and make a new blanc layer beneath the horse layer.
Use a splatter brush to make the splatters by rotating the brush.
View attachment 98902
Duplicate the watercolor layer and place it between the horse layer and the splatter layer.
Make the splatter layer active (ctrl+thumbnail to see the marching ants)
Clip the duplicated watercolor layer to the splatter layer and reduce the opacity at will (I used 30%)
View attachment 98903
Make the horse layer back active (click the eyeball) and if all went well you'll end up with
View attachment 98904