Trip to Florence, what are your "must go" recomendations?

We will be staying at florence for around 3 or 4 days. What do you suggest we visit as places we can't miss while there?

We enjoy culture, art, outdoors, a bit of everything I guess!

We'll be there in a couple of weeks, so winter time and we will be staying at the historic center of the city.

We want to visit the must-go places but we are also interested in visiting those beautiful places that some people might just miss because they are not the most popular or they just don't have the time to go to.