How to use water decals?

[Kodiyo]

I only know it should be plunged into water and slid it out from paper to fingernails.
Is there any further instruction I can follow?
How to keep it long?
How does it work with UV gel?
Is it perfect to match colors like these pictures: http://www.amio.cc/water-decal-c-67
Do you have better idea of color matching?

[you'vegotnail!]

Funny... there was a post a couple of days ago touting water decals from a brand new member. I can't help but notice that you provided the same link. I'm sure I'm not the only board member not fooled.