I thought I'd conduct some online research myself and I've come across a few fascinating methods for achieving the houndstooth nail. Obviously the skilled draftsman can painstakingly hand paint the pattern with duotone polish but most sane people would prefer a nail art stamping kit such as the ones made by Konad or Minx which Asami over at My Manicure and Siobhan over at The Nail Phile demonstrate to great effect.

Alternatively you can buy preconfigured houndstooth artificial nails like these japanese style versions at www.ayamisnail.com.

And here is a youtube tutorial on painting your own houndstooth.
And then maybe, just maybe, one day you may even surpass Lee Redmond as the title holder of the world's sexiest nails.

It's a slippery slope. And don't say I didn't warn ya.