This was definitely on my bucket list, and I got to cross it off in February of this year! All you have to do is show up in Saint Marks Square - the people in costumes do the rest! It is mind blowing the extend they go to in perfecting their costumes - you have to see it to believe it! The area around St. Marks is beautiful for photography - so many arches, doorways, and the backdrop of the Grand Canal. The people knew where to pose and gladly did so. Your only problem will be the jostling and the rudeness of some of the photographers trying to take pictures. Just be patient and wait your turn, even if the costumed people move along, they are just moving to another perfect location! The fun goes on all day - I found people to take pictures of from 9 am until at least 6 pm each day during the carnival festivities.