Since we're talking about trailers, I want to toss something out as it bit me in the butt.
If your trailer is more than about 10 years old, before you use it, give it a
thorough inspection before using it.
I consider a "normal" inspection is to check the tires for cracks and pressure, check all lights, vehicle connections and brakes if equipped.
On older trailers, crawl underneath and give it a full inspection. I had the U-bolts fail that hold the springs to the axle fail after hitting a large pot hole (the trailer literally jumped 5' into the air). Thankfully, the trailer was empty and I was able to limp it to my destination but I was 200 miles away from home and absolutely needed the trailer. A closer inspection showed a rear spring shackle (the one that's welded to the frame) was just about rusted through and although I was able to fix the U-bolts in the field, I didn't have a welder to weld on a new shackle.
I ended up buying a new trailer and had to leave this one behind.