When loading a 12000 pound tractor on a trailer with ramps, make sure that the rear of the trailer is supported! We've only made that mistake twice... a Ford 8600 is HEAVY and when we picked one up for cheap at an auction and loading it on a trailer we forgot to support the back, the trailer tongue (pintle hitch) and the rear of the F350 went a couple feet in the air until the tractor was far enough forward to bring it back down... the second time wasn't near as bad, but it was a 10000 pound boom truck on the same trailer... I guess this should go more in the stupid things being towed section but still...
as far as stupid tractor tricks, I'm an engineer so I try my best to do like stated earlier "how can this go wrong" but as we all know, that doesn't always work. I've mentioned in another post or two that I have some reed canary grass that I've been trying to control and mowing is usually involved to get the ground exposed but the ground not having any structure from the reed canary grass and the water table being just below ground level that gets interesting, last year was a record, I think I only got the tractor stuck once! maybe twice... not having a separate PTO clutch doesn't help, when forward motion stops but the brush hog is driving the tires when the clutch is pushed in just makes the tractor go down...
Aside from that it's just minor interference with the bucket and inanimate objects, tore a fence wire while mowing (same PTO issue mentioned above), hit a tree with the bucket, minor interference with the lean to tractor shed here and there, etc... last year I bought a one way clutch for the PTO so that part isn't an issue anymore...