How do I antique a red cabinet with black paint/stain?

Tracy, I'd dry brush some of the black on there. You might also try watering the black down and using a rag to apply it. I've done that before. It's almost like you paint it on and then take a bunch of it off. Send a picture when you complete it!

I would get a small 2 oz bottle of craft paint, and add glaze to it. The glaze slows down the drying process and also makes it more opaque (the more you add, the more opaque it gets). Paint it on, then rub it off so that it stays only in the corners and crevices. Rub off more or less to taste.

You might try a technique like Madison did here... http://www.hometalk.com/diy/bedroom/furniture/mineral-paint-makeover-28474324. If you have questions about her technique, you can ask her questions below the post and I know she'll answer them for you. :)