I live in the Netherlands. I buckle up right away after I start the engine. I don't care what everyone else in the car does, but they're paying their own ticket if they get caught.
I'm in the US, Florida. I buckle up right away, and make sure that anyone else that's in the car with me is buckled as well. Lives are worth too much to lose over a simple task.
I always made sure that I wear my seat belt even if I am parking my car on the side of my street I always wear a seat belt because you never know what's going to happen. I also always made sure to those who ride with me wear seat belts too
I get in the car, start the engine, and then buckle my seatbelt is how I usually end up doing it. I don't actually ask my passengers to fasten their seatbelts, as it's kind of a foregone conclusion. But yeah, I always wear my seatbelt.