Compare these 2 photos:

i just turned the original photo into a watercolor artwork using photoshop magic. (no it's not by applying the 'watercolor' filter ;) ). I've learned it from Igor Ulman's (
www.compartstudio.com) videolesson.
0. for achieving best results, it's good to have a blurry background and a big object(s) in the foreground with clear outlines. otherwise the objects in the background will add too much noise to your 'painting'. but of course you can just blur the background using the same photoshop :)
1. open the layers palete, and copy the background layer. until the end of this point we will work with the copy.
a. Desaturate the image (ctrl+shift+u).
b. now apply filter -> stylize -> Glowing Edges. suggested params are: edge width: 1 ; edge brightness: 11 ; smoothness: 5. but you can play with them of course. just be sure not to lose details!
c. Now open "levels" panel, and move the white slider towards the black one to enbrighten the image (suggested value: 116).
d. Now invert the image.
e. Apply filter -> artistic -> Cutout. suggested params are: number of levels: 7 ; edge simplicity: 3 ; edge fidelity: 3. Again you can play with the values (but again don't lose too much details!).
f. regulate the levels again. this time move the black slider to right until the dark gray lines of the outlined object are black. and now move the black slider of OUTPUT levels to 50.
g. set the blending type of this layer to "overlay" in layers palete
2. now copy the layer we were working with.
a. apply filter -> blur -> Gaussian blur and set radius to 5 px.
b. in layers palete set the blending type to "screen" and brightness to 50%
c. now create a clipping mask (ctrl + g)
3. now switch to "background" layer (original image)
a. apply filter -> noise -> median. suggested value of radius is 26 px, however it totally depends on the image and your taste :) the bigger the object, the bigger the radius.
The end.
however you can add a frame which will give your painting a final look.
see another example of what i did:

This is the boring original image. I changed the color of the lily to the left, applied this watercolor effect and added a frame. this is the result:

I hope you found this useful :) in the next post i will speak more about the frames.