I’ve bought & sold several homes due to transfers & moved overseas & back. It takes me about 6 months to get things throughly organized & situated. Much longer to really get things to my liking. I tackle a move into a new place by setting up the basics. I can leave things in boxes and come back to each room if needed. My goal is to get the place livable. I set up for function first and decorate second. I get the kitchen organized to the point I can make a meal. I usually need to ponder where stuff should go, but I get the basics in place and move on to other rooms. I establish some sort of office/work space so I don’t lose track of important paperwork or mail.
On the first floor I use my dining room as a staging area. Put all my pictures and lamps in the dining room and place things like vases & candles on the table.
As I decide where things should go I place them in the specific rooms. Sometimes I know right away if I like it, but I may live with it for a bit before deciding and hanging pictures on the wall. This allows me to try different combinations together. I always dislike moving out of a place, but enjoy moving to a new place much better.