Begin with what matters
Before measuring the new rooms, I like to ask which pieces you would miss. A painting, a table or a chair may hold something that a new purchase cannot replace. Make a short list of those pieces first. You are identifying priorities, not making every decision at once.
Give each piece a real place
A favorite piece deserves more than a spot where it just fits. Think about how you will use it and what needs to sit around it. A chest from a living room might be useful in an entry. A smaller table might become a desk. A familiar object can feel new in a different setting.
Measure the life around the furniture
A floor plan helps make the choices concrete. Allow space to open doors and drawers, pull out a chair and walk comfortably through the room. Check the route into the apartment too. A piece that fits the room still needs to fit through the door.
Leave room for something new
Keeping meaningful things does not mean recreating every room you had before. Sometimes one new light, a better chair or a different rug helps old and new pieces belong together. The goal is continuity with enough room for the life you want now.