imagine your mouth is like a syringe (sp? whatever: a doctors needle), and your tongue is the plunger part. fill your mouth with smoke, and then slowly push your tongue forward, which'll push the smoke out. the smoke'll naturally drift upward and all you need to do is inhale through your nose.

try getting fluent with the pushing action and inhaling at the same time.

it came easy to me cause i play digeridoo, and the same principle applies to cyclic breathing: so there is never a break in your playing, even when your taking breaths.

also, we call 'em irish waterfalls over here.