Start with a few layers of your primer coat.
I decided to go with a lighter shade of pink so added a few more layers of a powder pink acrylic. Then I used GOOP all purpose glue to add a strip of fabric to the back of each heel which I could lace some ribbon through. This process is key with such huge shoes or you can guarantee a wipout at some point in the evening;) Now they are secure .
Lastly ..the brain. Starting at the back of the heel I started adding bulging lines in black acrylic. its a long process but worth it. You could go symmetrical on both sides if you like, I decided to make each side different. If I was to keep working on these I would have added a black or dark burgundy outline along the blood dripping and would have added some white to add a bit of gleam to the blood.
Important Note: When painting shoes always choose a waterproof, permanent paint that is flexible or you will end up with cracks once you where them, and if you end up in rainy showers.. your still good;)