Venice is a roughly fish-shaped cluster of islands in shallow water off the Eastern coast of Italy.
If you're staying in the islands, take the train all the way to Venezia Santa Lucia.
Buy a continuous ACTV Public Transport pass for the public boat taxis (vaporetto) and busses. €20/1 day, €30/2 days, €40/3 days. Pass activates after the first swipe and will remain valid for the following 24/48/72 hours.
All transport costs/entry fees reduced if you are under age 26.
City streets are confusing but walkable. Download Ulmon offline map app. (link)
Register in advance online for a free walking tour. Three hours rain or shine. Tip your guide at the end. Lots of local insight and information like how to skip the huge queue at San Marco's Basilica. ;)
Don't try to see every island - most look the same. Do visit Murano (famous glass products and production) and Burano (a rainbow of architecture).
Pick three main museums or landmarks to make priority.
Free to go inside the famous San Marco Basilica.
Eat small, inexpensive tapas dishes at an authentic Osterilla.
AVOID all pizza and foods at the most touristic spots (Rialto Bridge, San Marco's Square) and places with huge, multi-page menus, pictures of the food or promoters trying to recruit you.
Watch the San Georgio limestone church (built by Palladio) glow at sunset.
Buy one thing: Murano glass accessory (jewelry, wine stopper, cuff links, etc) - many options under €10. Street stalls are cheaper than shops and items are usually cheapest on the other islands.
Cool books, postcards and stamps available at Acqua Alta bookstore.
Touristy Gondola rides are €80 for 30 minutes. Instead take a short trip across the canal in a "ferry Gondola" for €2.
I really loved Venice and want to come back here to live for a little while someday.