Venice Carneval should be a must for any aspiring ˝live˝ (i.e. non-studio) portrait photographer. Its collection (indeed, crowd) of exhibitionists, mememes and sheer weirdos makes one spoilt for choice. And yet, lest not to become too saturated too soon, one must be relaxed and simply hunt for the best.
The bonus is (as can be seen in the Portraits gallery on this site) that many unmasked people, ordinary visitors, will not object being photographed. Many will simply stop and pose, as if they are masked too. All part of the same show.