In my eight years of teaching I have taught in nine rooms. These are some things that I normally do that make this process easier.
1. Measure the new space. I measure the room, the desks and empty wall space. I make a blueprint for each room. This is not to be confused with a seating chart (which I also do). This is for me so that if I am wondering if that free bookshelf someone wants to get rid of will fit in my room, I can figure it out. I also keep photos of each room in my laptop or smartphone. I also shoot a video from the center while rotating.
2. Inventory the new room. Be sure to find out if anything is going with the old teacher or has been promised to someone else. Consider all wall space. What can be hung, mounted on the surface?
3. Be open to moving desks around. I know some people don't like to move the kids once the year starts and I am not one of those people. They are in the space for 40 minutes. I am there for 40+ hours per week. It has to work for everyone.
4. Plan storage for Wet and 3D items before setting up student desks. Room flow and easy access to sinks make for better clean up and happier teachers.
5. Label things as you unpack. It's frustrating to open 10 cabinets looking for a glue gun. Even if it's just painter's tape until you can make something pretty. I label my sinks (Sink 1, 2 and 3 or Sink A, B & C). Students are divided and informed of their sink assignment during first class where a sink is needed.
6. Use the change of room as a reason to purge. You know all the people who send kids to your classroom for a paintbrush, some colored pencils or other art tools? As you're weeding things out, make a curb alert pile outside your room. Even when I'm not changing rooms I've done this. People DO want your sloppy brush and your tiny nub of a colored pencil. I send a notice to the entire building and most of my "junk" is gone in less than 30 minutes.