This is something both Faith and I did as part of our Lammas celebration.
It was easy and fun, especially I think because we worked together, but you could do it on your own.

Here are two really good versions of home made scrying mirrors.

All you need for the first is a picture frame (with glass not plastic). A tin of gloss black enamel paint, and some 'decorating materials' for the frame once it is done.

Take the glass out of the frame and clean it really well.
Paint it with several coats of black paint. Keep going until you have a thick coat and no light comes through when you hold it up to a window.
Put the glass back in the frame and adjust the angle of the stand by cutting portions off the bottom of the stand post at the back until you have it at the right angle for you to look into comfortably.
Then you can do the fun bit. Decorating.

I painted the frame with the same black gloss paint and when it was dry I stuck silver stars and moons on it, with some curly lines and some seed beads.
I'll let Faith tell you what she did with hers, but lets just say there are some really bald black hens around here now!

The second version only needs a glass bowl or deep plate, the same black enamel paint and some water.
Paint the outside of the bowl/plate with several coats of enamel until the light won't come through, and then leave to dry. Then all you need to do is half fill the bowl with water, and there you have it, a reflective surface for scrying.
So hard to do!
Honestly this was so much fun, we had a real giggle and though we were absolutely hopeless when it came to actually using them, we're hoping that we will get better with practice.

Hope this is useful.

Darke

Ahh I wish I had thought of doing that before I bought one.
Which shapes did you choose, and how big are they?