Getting there: Delta and Sun Country fly nonstop in the winter from Minneapolis to Liberia, Costa Rica, 75 miles from San Juan del Sur and Ometepe. Take a pleasant, cheap bus ride from Liberia to the Nicaraguan border (a good resource on buses is at tinyurl.com/ycz9ftok). Cross the border on foot at Penas Blancas (info at tinyurl.com/yc94w4p9) and find a taxi or bus to your destination.
Airlines also fly to the Nicaraguan capital of Managua with stops; arrange ground transport with your hotel.
Casa Maderas Ecolodge: One of many options near Playa Maderas north of San Juan del Sur. From $18/night for a dorm; $42/night double. The lodge is set up for group yoga retreats with all-inclusive pricing (I paid $1,250 for a week), and offers yoga classes à la carte (casamaderas.com).
Tip: In Nicaragua, people selling travel services are polite, but may subtly lie to you for your business (by posing as officials or claiming there is no competition available). Do your homework and keep your wits about you, and you'll be fine.
Simon Peter Groebner