Most furniture regrets I see aren't about taste. They're about an inch or two that nobody checked. Before you click "order" on a sofa, a dining table, or a king bed, take twenty minutes and a tape measure to these five numbers — and write them on your phone, not on a sticky note that will disappear.
1. The narrowest doorway. Not the front door — every doorway between the truck and the room. A 39-inch sofa will not turn into an 80-degree hallway through a 32-inch door no matter how cheerful the delivery crew is.
2. The stair landing. If the piece is going up or down, measure both the stair width and the diagonal at the landing. The landing is almost always the choke point.
3. The wall behind the piece — wall to wall, not eye-balled. A 96-inch sofa centered on a 102-inch wall looks tight. The same sofa on a 132-inch wall looks lonely.
4. The walkway in front. You need 30 inches to walk past a coffee table comfortably and 36 inches behind a dining chair to push back from the table. Measure from the proposed furniture face, not from the wall.
5. The ceiling height. Tall headboards, canopy beds, and oversized art all photograph beautifully in 10-foot rooms and feel oppressive in 8-foot rooms. Know your ceiling before you fall in love with a piece online.
If any of these numbers make you nervous, that's the moment to send me a quick photo and a floor plan — not the moment to hope it works out.