How do you make sure furniture fits when moving or redecorating?

Moving and redecorating always comes with a “what if it doesn’t fit” fear. My last couch purchase nearly ended in disaster because the hallway was too narrow. I’ve seen services like ItemFits.com that can digitally check fit, rotation, and door clearance.

I’m curious: do people here rely on tech, just tape measures, or a mix? What’s your fail-safe method for avoiding the “it doesn’t fit” nightmare? Would love to hear tips from anyone who’s moved a ton or buys furniture online frequently.