mhhh, well i will advise you one thing use people experience to gather more knowledge but use your own experience to find what is best working for you. i have never used any of that, though one of my friend prefer to use water mixed with her drop of blood she describe it as the best medium for scrying.
but what you need to know about visions they are not formed outside of you rather they are formed on your minds eye. Thats why if you will have a vision of spirit formed on your head wherever you will look on the room you will see the spirit because the spirit first manifests within you and then you project that vision outside of you onto the scrying medium.
so first work on yourself the scrying medium will find you.