I confess I'd never dealt with this until we moved to the city. In the country, the new poop deposit in the ditch just added to the "country aroma" of the nearby cows and pigs.
When we moved to an apartment and I had to walk them everywhere, I brought a WalMart bag with me. The first time I gingerly put my hand in the bag, picked up the poop, turned the bag inside out and twisted it to "seal" it, I honestly thought, "Gosh, what was I worried about? Changing three babies' dirty diapers was LOTS worse!" Ha ha!