How do I make a 12”x12” silicone template for a resin cross?

The best way to find out this can of thing is to use Google.

https://www.diynetwork.com/how-to/make-and-decorate/crafts/how-to-make-resin-jewelry

Don't add the blood, kinda gruesome.

I'm so sorry for your loss Catherine. You had quite a few questions and hopefully we can answer some of them:

• Silicone mold - this article show you how to make one using only two ingredients - https://acraftymix.com/blog/2018/05/07/two-ingredient-mold/. It will work for any sized cross
• Chakra stone colors - this beautiful article explains all about the chakras and has a lovely cheat sheet that shows the different stones - https://www.energymuse.com/blog/chakra-stones-chart-chakra-awareness/
• Reiki - and this article explains how to use those stones for reiki healing - https://astrologyanswers.com/article/reiki-stones-how-to-use-reiki-stones-for-chakra-healing/

Sending lots of love

If you want to put red paint to symbolize Jesus blood then you go right on and do that! I don't think that's gruesome at all. Don't listen to negativity. Sorry for your awful loss. Some people don't understand others creativity. I had my engagement pictures taken in a cemetery and got married on the Day of the Dead. Everyone thought we were nuts till they saw the pictures and how beautiful they were. And when they came to the wedding and were in tears when they realized what that day actually represents. People always criticize their unknown. Have a happy day.