How to make your abs stand out more in an iPhone picture?

So some girls wanted me to take a picture of my abs while I'm shaving my beard at the end of this month (No-shave November). I have an iPhone 4S and it's going to be a mirror selfie.
I already have good abs (Six-pack) but I want them to really stand out in the picture.
Any ideas y'all?

I think some people shade it with makeup to make them look more defined. But you should really just be yourself. What happens if you hook up with one of then and they realize you don't look like that. Their gonna think you photoshopped yourself and call you pathetic.

Work out before, take the picture when your dehydrated. Don't eat anything before. No junk food or soda, you'll bloat.

That's how they do before and after pics on tv. They work out, stay dehydrated, take pics in great lighting.
Then drink a 2 liter of soda, eat a big bag of deritos, turn the extra lites off and boom they look out of shape.