A magic mirror or black mirror, is much like a crystal ball. It is used for scrying, and easy to make at home.
All you need is:
1 round mirror
1 can of black paint

Take the mirror and paint the back black and let dry, then once its dry cleanse and consecrate.

Spell of dedication:
I dedicate this magic mirror to my works,
May it do me good in all the days of my life,
This is my will, so shall it be!