How to avoid waiting in lines by sniem
Florence is full of tourists the whole year round, therefor it's almost inevitable to stand in lines to enter museums and churches. and gelaterias (in summer) In order to avoid this some places offer online prebooking of tickets. For the uffizi art gallery for instance they will give you a certain date and time to enter and you stand in a seperate line than the others. When I did this I still had to wait about 15 minutes to get in but thats nothing compared to 2-3 hours others have to wait.
You can reserve online through this link:
http://www.florenceart.it/booking/
I've also found out that for most places the best time to enter is late. So I visit the not so popular places, like the Bargello (my favourite museum - strange that it's not so popular) in the daytime and after 6pm go to the Academia for instance. You can just walk in, a few hours earlier the waiting line goes around the whole block.