What is the best way to market a yoga-exercise posture deck?

As a Pilates teacher selling items to clients and others, i would recommend first an email to all yoga studiOS in the US and European community explaining your products and its benefits. i would also target all chiropractors, osteopaths, physiotherapists, sports clinics and even Pilates studiOS as we all deal in one manner or another with posture related issues. If interested then you could send a flyer through the mail or email. If targeting other countries be prepared to quote a shipping rate and import duties/taxes and other details like for delivery. I hope that this helps. Good luck with your venture. Monique