Avoid mixing real pictures (aka photographs) with anime or 3d images. It must be a great master to do that (it's so hard I think I saw that just once) and most time it just don't fit, you get the clear idea what you did you joined the two images. Sometimes what I try to do is make the photograph looking like it was also drawn! So like that you don't know what I transformed or what was the original.
Also when it comes about water and crystal try to make a soft outline on the character in white, it'll get an idea of "pure".