A lot of NBA teams come into my work for practice, or if its the day of the game it is a shootaround. If it is not a game day, there are a few different things that the teams do. They usually take around 20 minutes to let the players shoot around, and then they huddle up, go over what they want to work on specifically that day, and then take a long time to warm up. The Mavs when they came in did a lot of shooting competitions to warm up, and some 3 man weaves and 5 man weaves. Some other teams just have them jog up and down with different dribbling moves. Most teams do not go hard at all, it is basically a little harder than walking. They usually break up into two different groups, with big men on one side and guards on the other, then do different drills like shooting, pick and rolls, and post moves.
After that they usually make groups and run their sets up and down the court for a few trips, just going over their plays. After that they usually get into a half court controlled scrimmage or a full court controlled scrimmage. If it's a half court scrimmage, they take turns running the opponent that they are going to play next (the Warriors are the case when they come to my work) and they work on how they want to play the pick and rolls depending on if its Curry, Ellis, Maggette, etc. so basically just so they can see their sets and everyone knows how it should be played and so everyone knows the calls to make. When they move to full court they usually just try to run their own sets, and teams like the Sixers play short games to 5, everything 1 point. The teams usually go hard at this time, and by far the Mavs were the hardest practice team I have seen so far this year. This is basically what they do, teams usually say they want to practice for 2 hours, but it never goes for that long, usually an hour and 15 minutes is how long they go, and most players ice up or talk to the media, and everyone who doesn't do that immediately just shoots a lot of shots til they leave.
If it is the day of the game, it is really a Walkthrough. Only one team so far this year came in and watched film, which were the Nets. Many players don't even take their sweats off, and a lot of them barely get a sweat going. They just take time and stay half court, going over the sets that the other team is going to run that night, and make sure they know even more what the tendencies of what the other team wants to do, and what they look for. There is some shooting done, and it only usually lasts an hour at most. I've seen several NBA teams this year, and this is what usually goes on. Hope that helps. All the players are really cool, and I feel really lucky that I get to watch them practice.