Getting around during Carnivale is frantic as the city is so crowded. It is also perishing cold. People in extravagant costumes are all heading for st mark's square, where there is the carnival ball into which the best dressed are admitted free. So the costumes to be seen parading by to be seen are qute something else.
However some carnival goers are umpty about being photographed. Seems odd to me, for someone to dress up as a camp version of a renaissance imagining of a roman general, then get upset when photographed, but just so you know.
The land route from the railway / bus terminal to st mark's square is clearly marked - and in any case just follow your the crowds - but is incredibly crowded at carnival. Take it as slowly as everyone else and as you pass the supermarket (I only found the one) go in and stock up, as cafe prices are BOGGLING especially if you just fancy a swift half or a nip of brandy.
St marks square is where everyone heads, and when I was there last year it was so busy you had you hold your camera above your head to take a photo. \like a football crowd without the swearing. Plenty of pushing though - after all, this is Italy. (continued)