Blowing the Perfect Smoke Ring with your Cigar
The biggest factor in blowing good smoke rings is practice. With that in mind, try this technique.
First, you need a cigar with dense smoke, and a place with still air. Don't waste your time trying to blow smoke rings in a breeze!
Draw a thick puff of smoke into your mouth. Hold it there and open your mouth slowly. Make an "O" with your mouth, (maybe more of a rounded "oh") - definitely not a pucker like a kiss. Curl the tip of your tongue down, and pull your tongue all the way back.
Now, when blowing a ring, you're actually not exhaling. You're just pushing out the smoke in your mouth with your tongue in short bursts - like a piston, only in a relaxed way. It's actually a really gentle motion. Push forward with your tongue, with perhaps a slight recoil at the bottom.
Practice makes perfect.